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Regional variations in endoplasmic reticulum in the vas deferens of normal and vasectomized rats.

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Regional Variations in Endoplasmic Reticulum in the
Vas Deferens of Normal and Vasectomized Rats
CHARLES J. FLICKINGER
Department of Anatomy, School of Medicine, University of Virginia,
Charlottesville, Virginia 22901
ABSTRACT
The fine structure of the epithelium of different parts of the rat
vas deferens was studied in normal rats and at intervals of up to nine months
after vasectomy. The cytology of the columnar epithelial cells showed regional
variations particularly in the type and extent of endoplasmic reticulum. Cells of
the proximal part of the vas deferens were characterized by basal and perinuclear granular endoplasmic reticulum, a large Golgi apparatus, and numerous
apical microvilli, vesicles, and vacuoles. In contrast, the columnar cells of the
distal portion of the vas deferens contained large amounts of smooth endoplasmic reticulum, much of which assumed the form of large whorls of smooth
membranes. In the distal segment the number of microvilli, vesicles, and vacuoles was less but mitochondria were more numerous than in the proximal part.
Cells in the middle portion of the vas deferens showed some features of both
proximal and distal parts. These structural characteristics, along with previous
experiments, suggest that in the proximal portion of the vas deferens absorption
of material from the lumen is an important function, while the cells of the distal
part may synthesize steroids. Thus, these regional differences in ultrastructure
probably reflect regional differences in function along the length of the vas
deferens. After vasectomy the regional specializations were retained and did not
appear to be altered. The possibility that this structural and functional sequence
is significant for normal fertility and its relation to attempts to reconnect the
vas deferens after vasectomy are considered.
Vasectomy has become increasingly sectomy as a means of contraception is
popular as a means of male contraception the irreversible nature of the operation. In
because the operation is rapid, inexpen- only a fraction of cases has it proved possive, and effective. Changes in the epididy- sible to restore normal fertility if this is
mis have been detected after vasectomy desired at a later time, even though anathat are consistent with the disposal of tomical re-anastomosis of the vas deferens
some sperm in this location (Phadke, '64; may have been achieved (Jhaver et al., '71;
Alexander, '71; Flickinger, '72), but most Gillette, '72; Hulka and Davis, '72).
As part of a study of the effects of vastudies have indicated that there are no
adverse changes in the testis (Oslund, '24; sectomy on the male reproductive tract,
Moore and Quick, '24; Young, '33; Poynter, samples of proximal and distal parts of
'39; Moore, '39; Amann, '62; Smith, '62; the vas deferens were prepared for elecKar et al., '65; Paufler and Foote, '69a; tron microscopy. It was observed that the
Flickinger, '73). It should be noted, how- cellular organelles of the epithelial cells of
ever, that the literature is not unanimous the vas deferens in these regions varied
on this latter point (Steinach, '20; Grewel
Received Nov. 9, '72. Accepted Jan. 19, '73.
and Sachan, '68; Kubota, '69), and only a
1 Supported by contracts 69-2104 and 71-2506 with
the
National Institute of Child Health and Human Defew ultrastructural studies of the testis velopment.
Portions of the work carried out at the
after vasectomy have been carried out University of Colorado were also supported by Program
Project
of the National Institutes of
(Kubota, '69; Flickinger, '73). In contrast Health HealthHD-02282
Sciences Advancement Award FRto these generally favorable features, one 06084 'from the National Institutes of Health, and a
Career Development Award from the Napersisting disadvantage to the use of va- Research
tional Institute of General Medical Sciences.
ANAT. REC.. 176: 205-224.
205
206
CHARLES J. FLICKINGER
markedly both in normal rats and after
vasectomy. Furthermore, these differences,
primarily in the type and extent of the
endoplasmic reticulum, are probably related to regional differences in function
along the length of the vas deferens. Two
implications of this observation are as follows. First, the vas deferens is apparently
not a simple tube or sperm conduit, but
seems to be more complex functionally
than previously supposed. Second, simple
mechanical continuity of the vas deferens
alone may not be sufficient for normal
fertility and its restoration after vasectomy, but the presence of a morphological
and functional sequence in the cells of
the epithelium may also be important.
MATERIALS AND METHODS
Adult male white rats, three to six
months old, were purchased from the
Holtzman, Co., Madison, Wisconsin. These
animals were subjected to either unilateral
vasectomy, bilateral vasectomy, or a bilateral sham operation.
The rats were anesthetized with ether
or nembutal, and the scrotum was incised.
The vas deferens was divided approximately at its mid point. As discussed in
previous publications (Flickinger, '72, '73),
different means of sealing the cut ends of
the vas deferens were used in an attempt
to reduce the number of animals that acquired a spermatic granuloma around the
proximal end of the vas deferens. In some
animals the ends of the vas deferens were
ligated with 3-0 black silk. In other rats
the ends of the vas deferens were crushed
with a hemostat and ligated with 3-0
plain catgut. The ends of the vas deferens
were cauterized with a hot spatula in a
few instances. In the sham operation, the
vas deferens was mobilized and ligatures
were passed around it as if to perform a
ligation, but the threads were then withdrawn. In all operations the peritoneum
was closed with 4-0 silk and the skin
edges were approximately with 2-0 silk or
metal skin clips.
A total of 21 animals was killed by
cervical dislocation at intervals of two
weeks and one, two, four, six, and nine
months after the operation. Samples of
the vas deferens were obtained from the
following locations. In the case of bilat-
erally vasectomized animals and the ligated side of unilaterally vasectomized
rats, slices of vas deferens were obtained
from approximately the mid point of both
the proximal and distal segments. That is,
the samples of the proximal portion were
taken from midway between the beginning
of the vas deferens at the cauda epididymidis and the point of ligation. Specimens
of the distal part were obtained from midway between the point of ligation and the
termination of the vas deferens in the prostatic urethra. On the control side of unilaterally vasectomized rats, in animals
subjected to a bilateral sham operation,
and in the initial series of normal unoperated control rats, samples were taken
from near the mid point of the vas deferens
or a few millimeters proximal to it.
When differences were detected between
the proximal and distal parts of the vas
deferens following vasectomy, a re-examination of normal animals was undertaken.
Samples of proximal, middle, and distal
parts of the vas deferens were prepared
in the following way. The entire length
of the vas deferens, about 5.0 to 5.5 cm,
was dissected. Measuring from the proximal (testicular) end, samples of the proximal part were taken from between 0.5
to 1.0 cm, specimens of the middle part
were obtained from 2.25 to 2.75 cm, and
samples of the distal portion were obtained
from 3.75 to 5.0 cm, depending on the
total length of the vas deferens.
In each case, transverse slices 1 mm or
less in thickness were cut using a razor
blade. The slices were fixed for two hours
in Karnovsky's fixative (Karnovsky, '65).
They were rinsed in distilled water and
postfixed for one hour in 1% Os01 in 0.1 M
cacodylate buffer at pH 7.3. The specimens
were dehydrated in a graded series of
ethanols followed by propylene oxide, and
embedded in Araldite. Sections 0.5 p thick
were cut with glass knives and stained
with 0.5% toluidine blue in 0.5% sodium
borate for light microscopy. Thin sections
showing silver to pale gold interference
colors were cut with a diamond knife on
a Porter-Blum MT-1 or MT-2 microtome
and were mounted on uncoated copper
grids. The specimens were stained with
lead citrate (Reynolds, '63) and examined
in a Philips EM-300 electron microscope.
ENDOPLASMIC RETICULUM I N THE VAS DEFERENS
RESULTS
207
Some columnar cells of the proximal
part
of the vas deferens after vasectomy
Proximal portion of the vas deferens
contained large membrane-bounded strucThe fine structure of the epithelium of tures identified morphologically as lysothe proximal part of the vas deferens in somes (fig. 4). Their content was variable,
both normal rats and after vasectomy cor- but occasionally consisted of bundles of a
responded closely to previous descriptions fibrous substance. The appearance of this
of the rat vas deferens (Orlandini, '63, '64, material was remniscent of the fibers of
'67; Orlandini and Pdlegrini, '70; Friend sperm tails, suggesting that some parts of
and Farquhar, '67). Small basal cells with sperm may have been absorbed by the
few organelles were present next to the epithelium of the proximal part of the
basal lamina. Most of the epithelium was vas deferens after vasectomy. Similar
composed of tall columnar cells (fig. 1). structures were observed in the proximal
An Oval nucleus was located in the basal part of the vas deferens of normal rats,
part of the cell. The basal and perinuclear however, and the total number of times
cytoplasm contained abundant anastomos- the large lysosomes were encountered was
ing cisternae of rough endoplasmic reticu- not sufficient to permit the conclusion that
lum (fig. 2). The large Golgi apparatus they increased in number after vasectomy.
(fig. 1) was located in a supranuclear
Distal portion of the vas deferens
position and was composed of stacks of
The most striking feature of the cosmooth cisternae with a multitude of
smooth and coated vesicles 400 A in diam- lumnar epithelial cells of the distal part
eter around the margins of the stacks. of the vas deferens in both normal and
Some cisternae of the rough endoplasmic vasectomized rats was the presence of
large amounts of smooth endoplasmic rereticulum were found lateral to the Golgi ticulum (figs. 5 , 6, 7). Cisternae of rough
region, but the amount of rough endo- endoplasmic reticulum were relegated to
plasmic reticulum declined toward the a relatively smaller area in the basal porapical ends of the cells while tubules of tion of the cytoplasm than in the cells
the smooth endoplasmic reticulum became of the proximal region. The Golgi apmore prominent (fig. 3 ) .
paratus was large and retained its supraMany microvilli were present on the nuclear location.
apical surface, and coated pits were
The extensive smooth endoplasmic represent between the microvilli (figs. 1, 3 ) . ticulum in the cells of the distal segment
The apical cytoplasm (figs. 1, 3 ) contained assumed two main forms (fig. 5). Tubules
large numbers of smooth and coated vesi- of smooth membranes were present as in
cles about 1000 A in diameter. A small the proximal part, but they were exceeded
number of large smooth vacuoles, multi- in number by numerous parallel unfenesvesicular bodies, and residual bodies were trated smooth cisternae, which were frealso present in the apical and supranuclear quently curved and arranged in a concencytoplasm. The apical surface of some tric pattern forming whorls of smooth
cells showed a large bulbous protrusion membranes of varying size. The apical
devoid of microvilli. The lumen contained parts of the cells often contained several
membrane bounded spheres of cytoplasm small whorls less than a micron in diamresembling the protrusions. Tubules and eter (fig. 6). Large whorls (fig. 7) several
some cisternae of smooth endoplasmic re- microns in diameter were present in the
ticulum were prominent in the protrusions perinuclear cytoplasm and sometimes exand detached spheres. Round and oval pro- tended into the basal regions normally OCfiles of mitochondria with plate-like cristae cupied by the rough endoplasmic reticu(figs. 1, 2) were scattered throughout the lum. The exact configuration of these
cytoplasm. Free ribosomes were present smooth membranes was difficult to ascerbetween the elements of rough endo- tain, but the precise definition of numerplasmic reticulum in the basal cytoplasm, ous parallel membranes in many sections
but diminished in number in the apical (fig. 5) suggested that they were cisternae
parts of the cell.
or flat sacs rather than tubules.
208
CHARLES J. FLICKINGER
Microvilli were present on the apical
surfaces of the cells of the distal segment,
and the apical cytoplasm (fig. 6 , 8) contained smooth and coated vesicles as well
as larger smooth vacuoles and lysosomes,
but these components were present in
smaller numbers than in the cells of the
proximal portion. On the other hand, a
relatively larger part of the cytoplasm of
the distal segment was occupied by abundant mitochondria (fig. 8). The mitochondria of the distal portion of the vas deferens were smaller, more numerous and
had more sinuous elongate profiles than
those of the proximal segment.
The degree of development of these features, especially the whorls of smooth endoplasmic reticulum, varied from one cell
to another in the distal portion. Many cells
contained large amounts of smooth endoplasmic reticulum, but a smaller number
of cells contained more rough endoplasmic
reticulum and resembled cells of the proximal segment.
Grossly the normal vas deferens increased progressively in diameter from the
proximal to the distal end, but there was
no discrete ampullary dilatation in the
distal part, as in some species. When
transverse sections were examined with
the light microscope, the thickness of the
smooth muscle coat was seen to be greater
in the distal portion than in the proximal
part. Adequate fixation of the epithelium
was more difficult to attain in specimens
from the distal part of the vas deferens
than in samples of the proximal portion,
possibly because the thicker muscle coat
impeded penetration of the fixative to the
epithelium.
The different forms of endoplasmic reticulum and other cell organelles in the
proximal and distal parts of the vas deferens were present both in normal rats
and in all the samples fixed at intervals
of up to nine months after vasectomy. Although quantitative morphometry was not
performed to determine whether the
amounts of rough or smooth endoplasmic
reticulum changed, the regional specializations were retained and did not appear
to be altered following vasectomy.
Middle portion of the uas deferens
Specimens from the intact vas deferens
of sham operated animals, the control side
of unilaterally vasectomized rats, and the
initial series of normal control animals
were taken from near to the mid-point of
the vas deferens or a few millimeters
proximal to it. The epithelial cells in these
samples showed a cytology generally similar to that described above for the proximal part of the vas deferens.
In later experiments we dissected the
entire vas deferens from normal rats and
attempted to relate the appearance of
samples more precisely to specific locations along the length of the vas deferens.
In samples taken from the true mid-point
of the entire vas deferens, which probably
lay several millimeters distal to those described immediately above, the epithelium
displayed some whorls of smooth endoplasmic reticulum (fig. 9). Although the
amount of smooth reticulum present was
considerably less than in samples of the
distal p-art, it exceeded that present in the
proximal portion. Thus, the cytology of
these samples of the middle segment
shared features of both proximal and
distal portions of the vas deferens.
DISCUSSION
The results show that there are pronounced regional variations in the cytology
of the columnar epithelial cells of the vas
deferens in normal rats, and that these
regional differences persist without apparent change for up to nine months after
vasectomy. The main difference between
the regions is in the character and the
extent of the endoplasmic reticulum. In
the proximal portion, the granular endoplasmic reticulum is the main form of the
organelle, but whorls of smooth endoplasmic reticulum predominate in the
distal part.
Whorls of smooth endoplasmic reticulum have been described in the mouse vas
deferens (Farrell, '69; Hamilton et al.,
'SS), but previous h e structure studies of
the rat vas deferens have usually described
cells lacking abundant smooth endoplasmic
reticulum and having a cytology similar
to that observed here in the proximal segment (Orlandini, '63,'64, '67; Niemi, '65;
Friend and Farquhar, '67; Orlandini and
Pellegrini, '70), although the presence of
small amounts of smooth endoplasmic re-
ENDOPLASMIC RETICULUM IN THE VAS DEFERENS
ticulum (Hamilton, '71) or the exisence
of some slender cells with an abundance
of smooth membranes (Orlandini and Pellegrini, '70) has been noted. In our initial
studies of normal rats, we also observed
little smooth endoplasmic reticulum. The
reason may be that upon opening the
scrotum the proximal part of the vas deferens is exposed and is the portion most
likely to be sampled. When we wished to
study the effects of vasectomy on the vas
deferens distal to the point of ligation,
however, it was necessary to obtain samples from the intra-abdominal part of the
vas deferens, and then the different cytological features of the distal portion were
discovered.
In the cells of the proximal part of
the vas deferens, the apical cytoplasm is
characterized by large numbers of coated
vesicles, vacuoles, and lysosomes. These
structural features suggest that this part
of the vas deferens epithelium functions
in absorption of material from the lumen.
The functions of these structures were delineated by the experiments of Friend and
Farquhar ('67). Protein is absorbed from
the lumen in large coated vesicles 1000 A
in diameter. Primary lysosomes in the
form of smaller 400 A coated vesicles are
produced in the Golgi apparatus, the hydrolytic enzymes presumably having been
synthesized in the granular endoplasmic
reticulum. The absorbed protein is incorporated into apical vacuoles, multivesicular bodies and other forms of lysosomes,
which acquire their content of hydrolytic
enzymes by fusion with primary lysosomes
derived from the Golgi apparatus.
In the distal part of the vas deferens,
on the other hand, smooth endoplasmic
reticulum in the form of extensive whorls
of membranes is the predominant organelle. A variety of functions has been
ascribed to the smooth endoplasmic reticulum (Fawcett, '65). Prominent among
them is a role in the synthesis of steroids
(Christensen and Fawcett, '61; '66; Christensen, '65; Christensen and Gillim, '69)
by virtue of the presence of many enzymes
of steroid biosynthesis in the membranes
of the smooth reticulum (Christensen and
Gillim, '69). Possibly the membranes also
provide a storage place for cholesterol
(Fawcett,, '65). The epididymis and vas
209
deferens of several species are capable of
in vitro synthesis of steroids (Frankel and
Eik-Nes, '68; Inano et al., '69; Hamilton
et al., '69; Hamilton and Fawcett, '70;
Fawcett and Hamilton, '70; Hamilton, '71)
including cholesterol and testosterone.
Combined morphological and biochemical
studies have implicated the extensive
smooth endoplasmic reticulum of the
mouse vas deferens in steroid synthesis
(Hamilton et al., '69). Since the rat vas
deferens has also been shown to be capable
of synthesizing cholesterol and testosterone
in vitro (Hamilton and Fawcett, '70), it
seems likely that this is one function of
the extensive smooth reticulum in the
distal part of rhe rat vas deferens.
The significance of the whorl-like form
of the smooth endoplasmic reticulum as
opposed to the tubular configuration is
debatable (Christensen and GiUim, '69;
cf., also Carr and Carr, '62; Christensen,
'65; Blanchette, '66; Christensen and Fawcett, '66; Bjersing, '67), as is the significance of fenestrated and unfenestrated
kinds of whorls. Studies on the mouse
epididymis and vas deferens, however,
have shown that the whorls of smooth reticulum in the vas deferens are more responsive to androgen replacement after
castration and may be more active in the
synthesis of cholesterol from acetate than
the tubular variety characteristic of the
caput epididymis (Hamilton, '71 ).
The present observations of regional
differences in the amount of smooth endoplasmic reticulum may account for the
apparent discrepancy be tween the biochemical demonstration of high activity
of the rat vas deferens in incorporating
acetate into testosterone, and the morphological observation of only relatively small
amounts of smooth membranes previously
detected in the rat vas deferens (Fawcett
and Hamilton, '70; Hamilton, '71). If morphological observations were made on the
proximal or middle part of the vas deferens, the content of smooth endoplasmic
reticulum would indeed appear low. But
when the distal part of the vas deferens
is considered, very large amounts of smooth
endoplasmic reticulum are present and
may be related to the high testosterone
synthesizing ability of the rat vas deferens.
210
CHARLES J. FLICKINGER
The functional significance of steroid
production in the vas deferens and epididymis is imperfectly understood at
present. It has been suggested, however,
(Hamilton et al., '69) that the steroids
may be secreted into the semen and may
affect sperm. Steroids are known to depress the metabolism of sperm (Gassner
and Hopwood, '55; Mounib, '64), and may
play some role in sperm capacitation
(Hamilton et al., '60).
Thus, it seems likely that these regional
differences in fine structure reflect differences in function in different parts of
the vas deferens. Coupled with other
studies showing the production of steroids
by the vas deferens (Hamilton et al., '69;
Hamilton and Fawcett, '70), this suggests
that the vas deferens is functionally more
complex than previously supposed. It appears to be not merely a simple tube or
conduit for sperm (Niemi, '65), but apparently contributes to the composition of
semen by its absorptive and secretory activity. The significance of the particular
arrangement or sequence of structural and
functional varieties of cells is not clear at
present, but it may have a role in normal
fertility. If the sequential arrangement of
different kinds of cells in the vas deferens
does have some significance for normal
fertility, regeneration of a normal epithelium with these cells in acceptable proportions and in proper sequence may be
necessary for the restoration of fertility
after vasectomy. Provided that similar regional differentiation exists in men, this
could be one factor that accounts for the
clinical observation that restoration of fertility is limited to only a part of the number of cases of apparently successful surgical reconnection of the vas deferens in
men (Jhaver et al., '71). In other words,
to restore fertility after vasectomy it may
not be sufficient to achieve a patent mechanical reconnection of the vas deferens,
but restoration of the different types of
cells in the adequate proportions and sequence without extensive missing segments may also be important.
Although differences between the epithelium of the proximal and distal parts
of the vas deferens are demonstrated in
the present study, the mode of transition
between the two regions, whether abrupt
or gradual, remains unclear. To answer
this question would require a systematic
study of a large number of samples at
intervals along the vas deferens. The observations made on the middle part of the
vas deferens in this study, however, suggest that there may be a gradual transition
from the characteristics of the proximal
segment to the features of the distal part,
beginning at about the mid-point of the
vas deferens. Samples from a few millimeters to the proximal side of the middle
of the vas deferens showed mainly a cytology similar to the proximal segment,
while samples of the true middle of the
vas deferens contained some small whorls
of membranes, suggesting that the cells
may progressively acquire larger amounts
of smooth endoplasmic reticulum with increasing distance along the vas deferens.
ACKNOWLEDGMENT
The author is indebted for technical assistance to Mrs. Stephanie Krah and Miss
Sharon Odum.
LITERATURE CITED
Alexander, N. J. 1971 Vasectomy: Effect on
the ductuli efferentes. Abstracts. American
Society for Cell Biology, New Orleans, p. 9.
Amann, R. P. 1962 Reproductive capacity of
dairy bulls. 111. The effect of ejaculation frequency, unilateral vasectomy, and age on
spermatogenesis. Am. J. Anat., 110: 49-67.
Bjersing, L. 1967 On the ultrastructure of
granulosa lutein cells in porcine corpus luteum,
with special reference to endoplasmic reticulum
and steroid hormone synthesis. Z. Zellforsch,
82: 187-211.
Blanchette, E. J. 1966 Ovarian steroid cells. 11.
The lutein cell. J. Cell Biol., 31: 517-542.
Carr, I., and J. Carr 1962 Membranous whorls
in the testicular interstitial cell. Anat. Rec.,
144: 143-147.
Christensen, A. K. 1965 The fine structure of
testicular interstitial cells in guinea pigs.
J. Cell Biol., 26: 911-935.
Christensen, A. K., and D. W. Fawcett 1961
The normal fine structure of opossum testicular interstitial cells. J. Biophys. Biochem.
Cytol., 9: 653-670.
1966 The fine structure of testicular
interstitial cells in mice. Am. J. Anat., 118:
55 1-572.
Christensen, A. K., and S. W. Gillim 1969 The
correlation of fine structure and function in
steroid-secreting cells, with emphasis on those
of the gonads. In: The Gonads. K. W. McKerns,
ed. North Holland Pub. Co., Amsterdam, pp.
415-488.
Fawcett, D. W. 1965 Structural and functional
variations in the membranes of the cytoplasm.
ENDOPLASMIC RETICULUM IN THE VAS DEFERENS
In: Intracellular membraneous structure. S.
Sen0 and E. V. Cowdry, eds. Japan SOC. for
Cell Biology, Okayama, pp. 1540.
Fawcett, D. W., and D. W. Hamilton 1970
Electron microscopical and biochemical evidence for steroid biosynthesis by the mammalian epididymis and vas deferens. In: Morphological Aspects of Andrology. Vol. I. A. F.
Holstein and E. Horstmann, eds. Grosse Verlag,
Berlin, pp. 119121.
Farrell, K. E. 1969 Ultrastructure of the
epithelium of the mouse vas deferens. J. Anat.,
104: 409.
Flickinger, C. J. 1972 Alterations in the fine
structure of the rat epididymis after vasectomy.
Anat. Rec., 173: 277-300.
1972 Ultrastructure of the rat testis
after vasectomy. Anat. Rec., 174: 477-494.
Frankel, A., and K. B. Eik-Nes 1968 Steroidogenesis i n vitro of the epididymis of the rabbit. Fed. Proc. Fed. Am. SOC.Exp. Biol., 27: 624.
Friend, D. S., and M. G. Farquhar 1967 Functions of coated vesicles during protein absorption in the rat vas deferens. J. Cell Biol., 35:
357-376.
Gassner, F. X.,and M. L. Hopwood 1955 Effect
of hormones on in vitro metabolism of bull semen. Proc. SOC.Exptl. Biol. Med., 89: 186-189.
Gillette, P. J. 1972 The vasectomy information
manual. Outerbridge and Lazard, New York,
p. 89.
Grewel, R. S., and M. S. Sachan 1968 Changes
in testicle after vasectomy. Experimental study.
Int. Surg., 49: 96-62.
Hamilton, D. W. 1971 Steroid function in the
mammalian epididymis. J. Reprod. Fert., Suppl.
13: 89-97.
Hamilton, D. W., A. L. Jones and D. W. Fawcett
1969 Cholesterol biosynthesis in the mouse
epididymis and ductus deferens. A biochemical
and morphological study. Biol. Reprod., 1 :
167-184.
Hamilton, D. W., and D. W. Fawcett 1970
In vitro synthesis of cholesterol and testosterone
from acetate by rat epididymis and vas
deferens. Proc. SOC. Exp. Biol. Med., 133:
693-695.
Hulka, J. I?., and J. E. Davis 1972 Vasectomy
and reversible vasocclusion. Fertil. Steril., 23:
683-696.
Inano, H., A. Machino and B-I. Tamaoki 1969
In vitro metabolism of steroid hormones by
cell-free homogenates of epididymides of adult
rats. Endocrinology, 84: 997-1003.
Jhaver, P. S., J. E. Davis, H. Lee, J. F. Hulka and
G. Leizht 1971 Reversibilitv of sterilization
produced by vas occlusion clip. Fertil. Steril.,
22: 263-269.
Kar, A. B., H. Chandra, and V. P. Kamboj 1965
Long-term effect of Vasectomy on the- eonadpituitary system of rats. Acta Biol. Med. germ.,
15: 381-385.
211
Karnovsky, M. J. 1965 A formaldehyde-glutaraldehyde fixative of high osmolality for use
in electron microscopy. J. Cell Biol., 27: 137A.
Kubota, R. 1969 Electron microscopic studies
on the testis after vasectomy in rats and men.
Jap. J. Urol., 60: 373497.
Moore, C. R. 1939 Biology of the testes. In: Sex
and Internal Secretions. E. Allen, C. H. Danforth and E. A. Doisey, eds. Williams and
Wilkins, Baltimore, pp. 353-451.
Moore, C. R., and W. J. Quick 1924 Properties
of the gonads as controllers of somatic and
psychical characteristics. VII. Vasectomy in the
rabbit. Am. J. Anat., 34: 317-336.
Mounib, M. S. 1964 Effects of certain hormones on the metabolism of bull spermatozoa.
Acta Endocrinol., 45: 631-640.
Niemi, M. 1965 The fine structure and histochemistry of the epithelial cells of the rat vas
deferens. Acta Anat (Basel), 60: 207-219.
Orlandini, G. E. 1963 L'epitelio del canale
deferente studiato a1 microscopio elettronico.
Arch. Ital. Anat. Embriol., 68: 199-212.
1964 La ultrastruttura della mucosa
del canale deferente nel ratto castrato, trattato
o meno con testosterone. Arch. Ital. Anat.
Embriol., 69: 185-213.
1967 Modificazioni ultrastrutturdi postnatali del l'epitelio del canale deferente di ratto.
Sperimentale, 11 7 : 253-281.
Orlandini, G. E., and M. S. Pellegrini 1970
The h e structure of the rat vas deferens during postnatal development. In: Morphological
Aspects of Andrology. Vol. 1. A. F. Holstein and
E. Horstmann, eds. Grosse Verlag, Berlin, pp.
131-135.
Oslund, R. 1924 A study of vasectomy on rats
and guinea pigs. Amer. J. Physiol., 67: 422443.
Paufler, S. K., and R. H. Foote 1969 Spermatogenesis in the rabbit following ligation of
the epididymis at different levels. Anat. Rec.,
164: 339-348.
Phadke, A. M. 1964 Fate of spermatozoa in
cases of obstructive azoospermia and after
lieation of vas deferens in man. J. Reprod.
Fertil.; 7: 1-12.
Poynter, H. 1939 Testis hormone secretion in
the rat under conditions of vasectomy or isolation. Anat. Rec., 74: 355-379.
Smith, G. 1962 The effects of ligation of the
vasa efferentia and vasectomy on testicular
function in the adult rat. J. Endocr., 23: 385399.
Steinach, E. 1921 Verjungung durch experimentelle Neubelebung der alternden Pubertatsdriise. Arch. Entw.-Mech. Org., 46: 557.
Young, W. C. 1933 Die Resorption in den
ductuli efferentes der Maus and ihre Bedeutung
fiir das Problem der Unterbindung in HodenNebenhoden-System, 2. Zellforsch., 17: 729759.
PLATE 1
EXPLANATION OF FIGURE
1
212
The apical part of a columnar epithelial cell from the proximal part
of the vas deferens. Many long slender microvilli ( a ) project from
the apical surface of the cell. There are coated pits ( p ) between the
microvilli. The apical cytoplasm contains numerous smooth and
coated vesicles ( v ) and a smaller number of larger smooth vacuoles
(b). The Golgi apparatus ( G ) is large and is composed of stacks
of smooth cisternae and small smooth vesicles. Mitochondria ( m )
have round or oval profiles and plate-like cristae. A centriole ( c ) is
visible. Normal rat. x 27,000.
ENDOPLASMIC RETICULUM I N THE VAS DEFERENS
PLATE 1
Charles J. Flickinger
213
PLATE 2
EXPLANATION OF FIGURES
2
In the proximal part of the vas deferens, basal and perinuclear
rough endoplasmic reticulum (RER) is the main form of the
organelle, n, nucleus; m, mitochondrion. Normal rat. x 22,000.
3 The apical parts of cells of the proximal segment contain tubules of
smooth endoplasmic reticulum (SER), in addition to numerous
vesicles (v). Microvilli ( a ) on the apical surface of the cell are
visible. Bilaterally vasectomized rat six months after operation.
X 28,000.
4
214
Some cells of the proximal part of the vas deferens both after
vasectomy and in normal rats contain large membrane-bounded
structures identified as lysosomes, which contain aggregates of a
fibrous material. Bilateral vasectomy, two weeks after operation.
x 21,000.
ENDOPLASMIC RETICULUM IN THE VAS DEFERENS
PLATE 2
Charles J. Flickinger
215
PLATE 3
EXPLANATION OF FIGURE
5
216
The cells of the distal part of the vas deferens contain much smooth
endoplasmic reticulum. This occurs in the form of tubules (T) or
closely apposed parallel cisternae (C). The cisternae are frequently
curved and arranged in a concentric pattern forming a whorl ( W )
of smooth membranes. Distal part of the vas deferens of a rat fixed
two weeks after bilateral vasectomy. x 28,000.
ENDOPLASMIC RETICULUM I N THE VAS DEFERENS
Charles J. Flickinger
PLATE 3
217
PLATE 4
EXPLANATION OF FIGURE
6
218
The whorls of smooth endoplasmic reticulum characteristic of the
distal part of the vas deferens vary in size. In the apical parts of the
cells small individual whorls ( W ) are present. Microvilli ( a ) are
present on the apical surface of cells in the distal segment, but
vesicles are less abundant in the apical cytoplasm than in the cells
of the proximal portion. Bilateral vasectomy, two weeks after operation. x 23,000.
END0PL)ASMIC RETICULUM IN THE VAS DEFERENS
Charles J. Flickinger
PLATE 4
219
PLATE 5
EXPLANATION OF FIGURE
7 Some of the whorls of smooth endoplasmic reticulum in the distal
part of the vas deferens are very extensive. The example shown in
this low magnification electron micrograph was more than ten microns wide, and all of its extent is not included in the field of view.
Distal part of the vas deferens two months after bilateral vasectomy.
x 19,000.
220
ENDOPLASMIC RETICULUM IN THE VAS DEFERENS
Charles J. Flickinger
PLATE 5
221
PLATE 6
EXPLANATION OF FIGURES
8
Mitochondria ( m ) are numerous in the cells of the distal part of
the vas deferens. In some cells much of the apical cytoplasm is
occupied by closely packed mitochondria. a, microvilli on apical surface; b, vacuole. Unilateral vasectomy, nine months after operation.
X 24,000.
9 Cells of the middle portion of the vas deferens contain features of
both proximal and distal segments. Some whorls of smooth endoplasmic reticulum ( W ) are present. These are less extensive than
in the distal portion (figs. 5 , 6, 7), but the amount of smooth endoplasmic reticulum in the middle portion exceeds that found in the
proximal part (figs. 1, 3). Sample from near the actual midpoint of
the vas deferens of a normal rat. X 22,000.
222
ENDOPLASMIC RETICULUM I N THE VAS DEFERENS
Charles J. Flickinger
PLATE 6
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