close

Вход

Забыли?

вход по аккаунту

?

The effects of 5╬▒-reduced androgens on maintenance and regeneration of prostate glands and seminal vesicles in castrated and hypophysectomized rats.

код для вставкиСкачать
The Effects of 5 ~ R e d u c e dAndrogens on Maintenance and
Regeneration of Prostate Glands and Seminal Vesicles in
Castrated and Hypophysectomized Rats
NAZIR AHMAD, DWIGHT W. WARREN AND GARY C. HALTMEYER '
Departments of Anatomy and Physiology, University of Southern California School of
Medicine, Los Angeles, California 90033
ABSTRACT
The effects of 5a-androstane-3a,l7/3-diol
(3a-diol) and 5aandrostane-3& 17P-diol (3P-diol) were studied in rats hypophysectomized and
treated daily for 30 days with the steroids, starting on the day of surgery
(hypophysectomized, H) or 30 days following the removal of pituitary (hypophysectomized regressed, HR). The ability of 3P-diol to maintain and restimulate
the prostate glands and seminal vesicles of castrated (C) and castrated
regressed (CR) rats, respectively, was also studied. This androgen (3P-diol) was
able to maintain as well as rejuvenate to some degree the sexual accessory
glands of all treatment groups. The prostate glands and seminal vesicles in
both castrated experimental groups showed increased stimulation with progressively higher dosages of 3P-diol. At all dose levels, stimulation of seminal vesicles of CR rats was comparable to t h a t of non-regressed castrates. The prostate
glands, on the other hand, showed better maintenance in the higher dosage
group. In H rats, the stimulation of sexual accessory glands by both androgens
was not significantly different than normal controls. The seminal vesicles and
prostate glands of HR rats treated with 3a-diol were well stimulated and comparable to those of H rats treated with 3a-diol. The seminal vesicles of HR rats
treated with 3P-diol were also well stimulated, though not to the extent as
those with 3a-diol treatment. The prostate glands of the 3P-diol treated HR
rats were significantly smaller than those of the 3a-diol treatment group. However, these miniature glands were morphologically stimulated as evidenced by
mitosis of parenchymal cells and accumulation of secretory products in the
alveoli. This study clearly indicates that 3P-diol is biologically active and the
degree of stimulation varies with the animal preparation in which the androgens were tested.
The biological activity of various androgenic steroids has been historically tested in
castrated rats where weights and/or morphological appearance of the ventral prostate
glands and seminal vesicles served as end
points. Only when the effects of these steroids
on maintenance or reinitiation of spermatogenesis needed to be studied, were hypophysectomized rats used. In this case, the effects
of a test steroid could be studied on the testes,
prostate gland and seminal vesicles simultaneously.
The biological activity of androgens has also
been studied in estrogen blocked male rats
(Steinberger and Duckett, '67; Chowdhury
ANAT. REC. (1978)192: 543-554.
and Steinberger, '75; Chemes et al., '76). This
animal preparation supposedly represents a
specific chemical hypophysectomy by blocking pituitary gonadotrophins. While most of
these preparations are quite complicated,
meaningful data have been generated by these
studies.
In view of some of the in vitro studies showing conversion of the major circulating androgen, testosterone, to other active metabolites
at the organ level (Farnsworth and Brown,
'63; Gloyna and Wilson, '69; Rivarola and
Podesta, '72; Folman et al., '73), studies have
Received Apr. 21. '78. Accepted June 27. '78.
' Deceased.
543
544
NAZIR AHMAD, DWIGHT W. WARREN AND GARY C. HALTMEYER
been performed utilizing the metabolites
themselves as precursors. When testicular tissue was incubated with 17P-hydroxy-5aandrostan-3-one (dihydrotestosterone, DHT),
t h e major conversion products were 5 a androstane-30,17P-diol (3a-diol) and 5aandrostane-3/3,17P-diol (3P-diol) (Sowell et
al., '74). In one of our studies, we incubated
tritiated DHT, 3a-diol or 3P-diol with tissues
from testes, prostate glands and seminal vesicles (Warren and Ahmad, '78). Prostatic and
testicular tissues were able to convert 3P-diol
to DHT and 3a-diol but seminal vesicles were
unable to perform this transformation.
The in vivo studies have clearly established
that DHT is capable of maintaining spermatogenesis as well as the prostate glands and
seminal vesicles (Ahmad et al., '73, '75). The
same effects have been attributed to 3a-diol in
hypophysectomized rats by Chowdhury and
Steinberger ('75) and Ahmad and Warren
('78) and to 3P-diol by Ahmad and Warren
('78). In castrated rats, 3a-diol has been
shown to maintain the prostate glands and
seminal vesicles while 3P-diol was ineffective
(Eldridge and Mahesh, '74). In an organ culture study of prostate glands, Robe1 et al. ('71)
reported that 3P-diol supported epithelial
height and secretory activity.
In addition to these divergent results regarding the biological activity of SP-diol, we
observed in pilot studies indications of key differences in terms of biological activity of some
androgen metabolites on the prostate glands
of castrated and hypophysectomized, regressed rats. The present studies were undertaken t o compare the biological activity of 3adiol and 3P-diol in various experimental animal preparations.
METHODS
Adult, Long-Evans, male rats were obtained
from Simonsen Laboratories, Gilroy, California and housed in an air-conditioned room under conditions of 14 hours of dark and 10 hours
of light. The animals were fed Purina rat chow
and water ad libitum. Groups of rats were
hypophysectomized via a parapharyngeal approach under ether anesthesia and the replacement therapy initiated either on the day
of surgery (hypophysectomized, H) or 30 days
following the removal of the pituitary (hypophysectomized regressed, HR). Also, groups of
rats were bilaterally castrated under ether anesthesia by a midline incision in the lower abdominal region and given 14 days of replace-
ment therapy starting with the day of surgery
(castrated, C) or 14 days following castration
(castrated regressed, CR). The numbers of animals assigned t o each experimental group and
the dosage of various hormones given are
shown in figures 1-4in the RESULTS section.
At necropsy, the testes, ventral prostate
glands and seminal vesicles in the case of H
animals, and the seminal vesicles and ventral
prostate glands in the case of C animals were
dissected free from the extraneous tissue,
weighed and fixed in Bouin's fluid, and embedded in nitrocellulose. Approximately 7 m p
thick sections were stained with periodic acid
Schiff's (PAS) and hematoxylin. The hormones were dissolved in corn oil and the concentrations adjusted so that the desired hormone was delivered subcutaneously in 0.2 ml
or less. Comparisons of various treatment
groups by analysis of variance yielded an overall P value of less than d.01 for all analyses.
The P value for individual comparisons are
given with each subgroup.
RESULTS
The results of various treatment regimens
are given in figures 1through 4. The morphological appearance of the control tissues is
shown in figures 5 through 9. The ventral
prostate glands of C rats treated daily with
various dosages of 3P-diol starting with the
day of surgery, showed a progressive increase
in weight with increasing dosage of the hormone (fig. 1). At all dose levels studied, the
prostate glands were significantly (P < 0.001)
heavier than untreated controls. However,
even a t the 2 mg daily dose, the weights did
not equal the normal controls (P < 0.001). The
CR rats which received the same dosages of
hormones two weeks following surgery showed
a similar dose dependent response, but the
weights of prostates at each dose level were
significantly (P < 0.001) lower than the C
treatment groups. It should be noted that the
duration of treatment for the regressed groups
was twice that of non-regressed rats. Morphologically, the prostate glands of operated control groups were atrophic (fig. 8) and those
from both treatment regimens were well stimulated. At the 1 and 2 mg dose levels the
glands were histologically indistinguishable
from the normal controls. The cells were tall
columnar with a supranuclear, negative Golgi
image (fig. 13). The secretory units contained
variable amounts of material that were PAS
positive (fig. 13).
5a-REDUCED ANDROGENS EFFECTS ON MALE ACCESSORIES
545
T
400
mg.
300
200
100
1
4
1
3
1
6
5
4
5
5
Fig. 1 The weights of t h e prostate glands of castrated and castrated regressed rats. On t h e left side are
t h e weights of the prostate glands of normal term controls , C term controls 5,
and C rats treated with
either 0.5 mg
or 1.0 mg
or 2.0 mg
of 3P-diol daily subcutaneously for 14 days, starting with t h e day
of surgery. On the right side are t h e weights of the prostate glands of the appropriate controls and CR rats
treated as above, starting 14 days following surgery for 28 days. The standard errors are indicated by vertical
bars and t h e number of rats are represented below the bars.
m,
a,
m,
1.5
gm.
I
1.0
0.5
6
0
3
1
6
5
4
5
5
Fig. 2 The weights of the seminal vesicles of castrated and castrated regressed rats. On the left side are
the weights of t h e seminal vesicles of normal term controls , C term c o n t r o l s 3 , and C rats treated with
either 0.5 mg D, or 1.0mg t881, or 2.0 mg @, of 3P-diol daily subcutaneously for 14 days, starting on the day of
the surgery. On the right side are t h e weights of t h e seminal vesicles of the appropriate controls and CR rats,
treated as above, starting 14 days following surgery for 28 days. The standard errors are indicated by vertical
bars and t h e number of rats i n each group is represented helow t h e bars.
Data on the seminal vesicles of C and CR
treated rats with 3P-diol are summarized in
figure 2. The seminal vesicles of the C and CR
rats also showed a progressive increase in
weights with higher dosages. However, as contrasted with the prostate glands (fig. 11, the
weights of the seminal vesicles of the CR rats
a t the 2 mg dose were not significantly different than C treated rats. Morphologically,
the seminal vesicles of untreated castrate controls were atrophic a t both intervals studied,
except that the atrophy was quite advanced a t
the longer duration. The cells were low cuboidal in appearance with virtually no evidence
of secretory material in the lumen of the
glands (fig. 9). Treatment with various dosages of 3P-diol caused stimulation of the seminal vesicles of C and CR rats (fig. 11). At the
highest dose level, the glands could not be
morphologically distinguished from normal
controls.
The effects of daily treatment with 1 mg of
3cu-diol or 3P-diol for 30 days on the prostate
glands in H and HR rats are summarized in
546
NAZIR AHMAD, DWIGHT W. WARREN A N D GARY C. HALTMEYER
Fig. 3 The weights of the prostate glands of hypophysectomized and hypophysectomized regressed rats.
On the left side are the weights of the prostate glands of normal term controls , H term controls L H rats
treated daily, subcutaneously with 1 mg of 3 u - d i o l 3 , and 3 P - d i o l a , for 30 days, starting with the day of surgery. On the right side are the weights of the appropriate controls and HR rats treated as above starting 30
days following surgery. The standard errors are indicated by vertical bars and the number of rats are represented below the bars.
J,
1.5
gm.
1.0
0.5
6
I
10
13
Fig. 4 The weights of the seminal vesicles of hypophysectomized and PHR rats. On t h e left side are the
weights of the seminal vesicles of normal term controls , H term controls E, H rats treated daily subcutaneously with 1 mg of 3 0 - d i o l c , and 3P-diol@, for 30 days, starting with the day of surgery. On the
righthand side are the weights of the seminal vesicles of appropriate controls and HR rats treated as above,
starting 30 days following surgery. The standard errors are indicated by vertical bars and the number of rats
are represented below the bars.
figure 3. The prostate glands of 3P-diol treated
HR rats were significantly smaller (P <
0.001) than normal, 3a-diol treated H and HR,
3P-diol treated H rats and C rats given the
same daily treatment. The prostate glands of
HR rats were also significantly smaller (P <
0.001) than CR rats given the same daily dose
of 3P-diol. Morphologically, the glands were
smaller (fig. 121, the secretory units were
filled with flocculent secretion not as in-
tensely PAS positive as in the case in normal
or 3a-diol treated rats. While precise quantification was not contemplated a t the outset
of the experiment, or performed, examination
of random sections of prostate glands of both
H and C rats treated with 3P-diol show considerably more mitotic activity in the parenchymal elements than one encounters in the
normal glands (figs. 14, 15).
Data on the seminal vesicles of H and HR
5a-REDUCED ANDROGENS EFFECTS ON MALE ACCESSORIES
rats treated with 1 mg 3a-diol or 3P-diol are
presented in figure 4.The seminal vesicles of
untreated H and HR rats were atrophic and
not significantly different from each other.
Morphologically, they were comparable to untreated castrate controls (fig. 7). Both metabolites stimulated t h e seminal vesicles of H as
well as HR rats. Stimulation by 3u-diol in
both groups was not significantly different
from t h e normal controls. Based on organ
weights, t h e restimulation of seminal vesicles
by 3P-diol was significantly (P < 0.001) less
t h a n t h e normal or 3a-diol treated rats. As
compared with t h e C rats given t h e same daily
dose of 3P-dio1, t h e seminal vesicles of H rats
were significantly larger (P < 0.001). The
seminal vesicles of HR and CR rats on t h e
same regimen were not significantly different
from each other. Morphologically, t h e seminal
vesicles of both groups of rats treated with 3pdiol were well stimulated and indistinguishable from normal and those treated with
3a-diol (fig. 10). With t h e identical staining
procedure t h e nuclei of stimulated seminal
vesicles (figs. 10, 11)and prostate glands (figs.
12-15) stained considerably lighter than appropriate unstimulated control glands
(figs. 6-91.
DISCUSSION
The results of t h e present study regarding
maintenance and restimulation of t h e prost a t e glands and seminal vesicles in H, C, and
CR rats with 3a-diol are in agreement with
several reported studies (Eldridge and Mahesh, '74; Chowdhury and Steinberger, '75;
Robel e t al., '711.
As previously stated, biological activity of
3P-diol is controversial. We have convincingly
shown t h a t in H rats, 3p-diol is capable of
maintaining spermatogenesis (Ahmad and
Warren, '78). In t h e present study, t h e d a t a
clearly support t h e conclusion t h a t in C rats,
this androgen can maintain and, in CR rats,
restimulate t h e seminal vesicles and prostate
glands. Only in HR rats, t h e restimulation of
t h e prostate glands is minimal.
While our studies are not strictly comparable t o t h e prostate organ culture studies of
Robel et al. ('711, our results are partly in
agreement with their findings. Our results
differ from those reported by Eldridge and
Mahesh ('74). The difference may in part be
explained by t h e amount of hormone administered and t h e age of t h e animals used andfor
t h e duration of t h e experiment. The above
547
mentioned authors used immature castrated
rats and treated them with lower dosages of
hormones for only one week. Moreover, t h e
bioactivity was assessed only by organ
weights and not by histological examination.
The present studies assign basically t h e same
biological function to 3p-diol as has been a t tributed t o DHT and 3a-diol (Ahmad e t al.,
'73, '75; Chowdhury and Steinberger, '75). The
problem remains, however, t o determine if all
three of these 5a-reduced androgens a r e biologically active or if they a r e interconverted t o
some active form. The conversion of DHT t o
3a-diol in r a t testicular tissue has been demonstrated in vitro by Rivarola and Podesta
('721, Rivarola et al. ('721, Folman et al. ('73),
Sowell e t al. ('74) and Warren and Ahmad
('78). Additionally, Sowell et al. ('74) and Warren and Ahmad ('78) have shown t h e formation of 3P-diol from 3u-diol and DHT in r a t
testes and demonstrated this same reaction in
prostate glands and seminal vesicles. It has
also been shown t h a t 3P-diol can be converted
to 3a-diol and DHT by r a t prostate tissue
(Becker et al., '73; Krieg e t al., '75; Warren
and Ahmad, '78). Warren and Ahmad ('781,
however, were unable to detect conversion of
3P-diol to other 5a-reduced metabolites by r a t
seminal vesicles. The action of 3u-diol and 38diol demonstrated in these studies cannot a s
yet be attributed directly t o these compounds
since conversion in t h e target tissue, or a t a
peripheral site with subsequent transport to
t h e target tissue, may be involved for biologic
action of these steroids. Further studies are
needed t o resolve t h e question of biological activity in a specific metabolite.
The unexpected findings t h a t 3P-diol is unable t o restimulate t h e prostate glands of t h e
HR rats t o t h e same extent as those of castrated regressed rats requires further investigation. Even though t h e regression of t h e sexual accessory glands of castrated rats at t h e
end of two weeks is comparable to t h a t of four
weeks in HR rats, t h e additional two weeks
may result in significant changes in t h e receptor proteins and/or necessary enzymes. Furthermore, t h e presence of pituitary hormones
in t h e CR rats may also have a beneficial effect at t h e organ level. This is in part indicated by t h e work of Grayhack et al. ('55) and
Slaunwhite and Sharma ('77). In t h e latter
study t h e prostate glands of H rats showed
increased s t i m u l a t i o n when testosterone
therapy was supplemented with prolactin.
548
NAZIK AHMAD, DWIGHT W. WARREN AND GARY C. HALTMEYER
ACKNOWLEDGMENTS
This work was supported by Research Grant
R01-HD-08126 from t h e National Institutes
of Health, Bethesda, Maryland.
The authors thank Ms. Linda Melsek for her
technical assistance and Ms. Cindy Blees for
her typing of this manuscript.
LITERATURE CITED
Ahmad, N., G. C. Haltmeyer and K. B. Eik-Nes 1973 Maintenance of spermatogenesis in rats with intratesticular
implants containing Testosterone or Dihydrotestosterone
(DHT). Biol. Reprod., 8: 411-419.
1975 Maintenance of spermatogenesis with Testosterone or Dihydrotestosterone. J. Reprod. Fertil., 44:
103-107.
Ahmad, N., and D. W. Warren 1978 In uiuo effects on spermatogenesis andin uitro metabolism of 5o-androstan-3p.
17fi-diolby testes, prostate glands and seminal vesicles.
Proceedings of Fifth Annual Workshop on the Testis,
Geilo, Norway, International Journal of Andrology, Suppl. 2: 494-505.
Becker, H., E. Grabosch, C. Hoffman and K. D. Voigt 1973
Metabolism and mode of action of androgens in target tissues of male rats. Acta Endocrinologica, 73: 407-416.
Chemes, H. E., E. Podesta and M. A. Rivarola 1976 Action
of Testosterone, Dihydrotestosterone and 5u-Androstan3u. 17fi-diol on spermatogenesis of immature rats. Biol.
Reprod., 14; 332-338.
Chowdhury. A. K., and E. Steinberger 1975 Effect of 5ureduced androgens on sex accessory organs, initiation and
maintenance of spermatogenesis in the rat. Biol. Reprod.,
12: 609-617.
Eldridge, J. C., and V. P. Mahesh 1974 Gonadal axis before
puberty. Evaluation of testicular steroids. Biol. Reprod.,
1 1 : 385-397.
Farnsworth, W. E., and J. R. Brown 1963 Testosterone metabolism in the prostate. In: Biology of the Prostate and
Related Tissues. National Institute Monograph. E. P.
Vollmer, ed., 12, 323.
Folman, Y., N. Ahmad, J. G. Sowell and K. B. Eik-Nes 1973
The formation in uitro of 5u-dihydrotestosterone and
other 5u-reduced metabolites of "H-testosterone by the
seminiferous tubules and interstitial tissue of immature
and mature rat testis. Endocrinology, 92: 41-47.
Gloyna, R. E., and J . D. Wilson 1969 A comparative study of
t h e conversion of testosterone to 17p-hydroxy-5uandrostan-3-one (Dihydrotestosterone) by prostate and
epididymis. J. Clin. Endocrinol., 29: 970-977.
Grayhack, J. T., P. L. Bunee, J. W. Kearns and W. W. Scott
1955 Influence of the pituitary on prostatic response to
androgen in the rat. Bull. Johns Hopkins Hosp., 96:
154-163.
Krieg, M., H. J . Horst and M. L. Sterha 1975 Binding and
metabolism of 5u-androstane-3u, 170-diol and of 5aandrostane-30, 17p-diol in t h e prostate, seminal vesicles
and plasma of male rats: Studies in uiuo and in uitro. J.
Endocr., 64: 529-538.
Rivarola, M. A., and E. J. Podesta 1972 Metabolism of testosterone-C'' by seminiferous tubules of mature rats:
Formation of 51r-androstan-3u, 17fi-di01-C'~.Endocrinology, 90: 618-623.
Rivarola, M. A,, E. J. Podesta and H. E. Chemes 1972 h
uitro testosterone-C'4 metabolism by rat seminiferous
tubules a t different stages of development: Formation of
5u-androstandiol a t meiosis. Endocrinology, 91: 537-542.
Robel, P., H. Lasnitski and E. E. Baulieu 1971 Hormone
metabolism and action: Testosterone and metabolites in
prostate organ culture. Biochimie, 53: 81-96.
Slaunwhite, W. R., Jr., and M. Sharma 1977 Effects of
hypophysectomy and prolactin replacement therapy on
prostatic response to androgen in orchidectomized rats.
Biol. Reprod., 17: 489-492.
Sowell, J. G.. Y. Folman and K. B. Eik-Nes 1974 Androgen
metabolism in rat testicular tissue. Endocrinology, 94:
346-354.
Steinberger, E., and G. E. Duckett 1967 Hormonal control
of spermatogenesis. J. Reprod. Fertil. (Suppl.), 2: 75-87.
Warren, D. W., and N. Ahmad 1978 In uitro conversion of
5a-reduced metabolites by t h e testes, ventral prostate
glands and seminal vesicles of adult rats. Steroids, 31:
259-267.
5a-REDUCED ANDROGENS EFFECTS ON MALE ACCESSORIES
Nazir Ahmad. Dwight W. Warren and Gary C. Haltmeyer
F’I.ATE 1
EXPLANATION OF FIGURES
5 Atrophic prostate glands of rat sacrificed 60 days following hypophysectomy. The secretory units are small, the cells are low cuboidal and t h e lumen is devoid of secretory product. Stained with PAS, Hematoxylin. X 98.
6 A higher magnification of a prostate gland shown in figure 5. Stained with PAS,
Hematoxylin. X 625.
7 The seminal vesicles of 60-day HR rat showing regressed parenchymal cells a t a
higher magnification. Stained with PAS, Hematoxylin. X 390.
549
5,r-REDUCED ANDROGENS EFFECTS ON MALE ACCESSORIES
Nazir Ahmad. Dwight W. Warren and Gary C. Haltmeyer
EXPLANATION O F FIGURES
8
A portion of a prostate gland of a rat necropsied four weeks following castration.
The epithelial cells have rounded up and show no secretory activity. Stained with
PAS, Hematoxylin. X 625.
9 The atrophic seminal vesicles of the same rat shown in figure 8. Stained with PAS,
Hematoxylin. X 625.
550
PLATE 2
5u-REDUCED ANDROGENS EFFECTS ON MALE ACCESSORIES
Nazir Ahmad, Dwight W. Warren and Gary C. Haltrneyer
PLATE 3
EXPLANATION OF FIGURES
10 A well stimulated seminal vesicle of rat treated daily for 30 days with 1 mg of 3udiol starting 30 days following hypophysectomy. The active secretory epithelial
cells are tall columnar and t h e lumen is filled with t h e secretory product. Stained
with PAS, Hematoxylin. X 625.
11 Seminal vesicles of a r a t treated for two weeks with a daily dose of 1 mg 38-dio1,
starting two weeks following castration. The epithelium is active and the lumen is
distended with the product of secretion. Stained with PAS, Hematoxylin. X 625.
55 1
PLATE 4
EXPLANATION OF FIGURES
12 The prostate glands of HR rat treated with a daily dose of 1 mg 3P-diol for 30 days.
The glandular epithelium is stimulated and the lumen contains some flocculent secretory product. Stained with PAS, Hematoxylin. X 390.
13 Stimulated prostate glands of castrate regressed rats injected daily with 1 mg of
3P-diol for two weeks. Supranuclear negative Golgi region is indicated by an arrow.
Stained with PAS, Hematoxylin. X 390.
14 A higher magnification of prostate glands from figure 12 showing mitotic figures
(arrows). Stained with PAS, Hematoxylin.
X
625.
15 A higher magnification of figure 13, showing mitotic activity of secretory epithelium (arrows). Stained with PAS, Hematoxylin. X 625.
552
5u-REDUCED ANDROGENS EFFECTS ON MALE ACCESSORIES
Nazir Ahmad, Dwight W. Warren and Gary C. Haltmeyer
Документ
Категория
Без категории
Просмотров
0
Размер файла
835 Кб
Теги
effect, vesicle, seminar, androgen, gland, maintenance, regenerative, rats, castrated, hypophysectomized, reduced, prostate
1/--страниц
Пожаловаться на содержимое документа