Sex differences in the proportion of the cortex and the medulla in the chicken suprarenal.код для вставкиСкачать
S E X DIFFERENCES I N THE PROPORTION O F THE CORTEX AND THE MEDULLA I N THE CHICKEN SUPRARENAL F. C. S A U E R AND HOMER B. L A T I M E R Department of Anatomy, University of Kansas This study is an attempt to throw light on the relationship between the weights of the cortex and medulla of the suprarenal gland of the chicken and the sex of the chicken. It has been shown that the size of the adult mammalian suprarenal is considerably greater in the female than in the male; that the difference is due to the presence of a greater amount of cortical material in the female glands ; and that a relation exists between the quantity of the cortical substance and the development of the secondary sex characters. Jackson (’13) finds that in general the female suprarenals are heavier in the albino rat. Hatai (’13) finds the suprarenals heavier in the female rats; he says: “The sex difference becomes clearly marked in rats of about 30 grams in body weight. The difference becomes greater as the rats increase in weight.’’ J. C. Donaldson (’19) shows graphs which indicate that the suprarenals of the female albino rat are about one and one-half times as heavy as those of the male. The glands of the females were found to contain relatively less medulla than those of the males, indicating that the difference in gross weight represents a greater amount of cortex in the females. H. H. Donaldson (’24), in studying the rat suprarenals, says : The volume of the medulla relative t o the entire gland decreases rapidly from birth to 50-100 grams of body weight, after which it increases in the male but remains constant in the female. The greater weight of the suprarenal in the female is therefore due mainly to the greater weight of the cortex. 289 290 F. C. SAUER A N D H. B. LATIMER Hill ( '30) finds that in primates, carnivores, and ungulates at time of birth the female suprarenal is larger. It is evident that in the mammals which have been studied, the female has more cortical material in proportion to the body weight than the male. However, it has been found that there is no apparent difference in the weight of male and female suprarenal glands in chickens (Latimer, '24). This study is an attempt to determine whether or not there is a difference in the proportion of cortical and medullary material in the glands of chickens such that the female may have a greater quantity of cortical substance than the male. MATERIALS AND METHODS The glands studied were taken from nineteen single-comb White Leghorn chickens from a local poultry company. Vigorous adults were selected, ten cocks and nine hens. The glands of the cocks were taken between October 5 and November 21,1929, and those of the hens between October 7 , and November 11, 1930, or at the same period of the year in each case, so that any seasonal changes in the glands would not affect the result. The birds were killed by bleeding from the jugular veins and the glands removed rapidly and freed from adhering fat and connective tissue as completely as possible without injuring them. They were then dropped into Zenker's fluid in individual weighing bottles and the weight of each gland determined from the increase in weight of the bottle and contents. The glands were all fixed in Zenker's and stained with Delafield's haematoxylin and Griibler 's alcohol-soluble eosin, 0.5 per cent solution in 70 per cent alcohol. Other eosins tried did not give good differentiations. The procedure was the same f o r every gland, so that any difference in shrinkage of the various materials in fixation would not affect the result. All of the glands were sectioned and mounted. Two were not used, as noted in tables 1 and 2. The glands were designated by the serial number of the bird and R or L to indicate SEX DIFFERENCES IN THE CHICKEN SUPRARENAL 291 right or left gland. Glands of the first two cocks were sectioned to a thickness of 7 p. All others were sectioned to l o p . For birds 1 to 5, all sections were mounted. For the remainder, every fifth section was mounted. The relative volumes of the various materials in each gland were determined by projecting areas of the stained sections on paper, drawing the outlines of the areas of the various materials, and then separating these and determining their weight. Glands 6L, 6R, and 7L were sampled by setting the mechanical stage of the projecting microscope successively to predetermined readings which represented points distributed over the entire slide, and drawing the field at each point. The circular field drawn was 9 inches in diameter, and at least fifty fields were drawn for each gland. The remainder of the glands were sampled by taking strips from center to edge of sections spaced equally throughout the gland. At least fifty fields were drawn for each gland. These were rectangular, 6 x 8 inches. The material of the areas drawn was labeled as cortex, medulla, blood spaces, and extraneous. The latter included the capsule, ganglion cells, fat, or any other adherent material. I n glands 3L, 3R, and 17L lymphoid infiltration was found in sufficient amounts to be drawn, and this was kept separate from the other areas, but is included with extraneous material in table 1. The method of determining areas by weight was that used by Jackson ( ’17) and Rasmussen ( ’28). Scammon and Scott (’27) investigated the relative merits of a number of methods f o r estimating areas. They found the planimetric method good for large areas, but it was found to give large errors when used to measure small areas, and for these the ‘area by weight’ method was found better. As the method assumes constant weight per unit of area, the variability of weight of the paper was investigated. Paper of good grade was found to have a coefficient of variation of 2.50. Eastman ‘Kodaloid, no. 3’ was found better in this respect, having a coefficient of variation of 1.62. Paper used for drawing the sections in T H E ANATOMICAL RECORD, VOL. 5 0 , NO. 3 292 F. C. SAUER AND H. B. LATIMER this study was Scriptum Ledger, 19 X 24-inch sheets, 44 pounds to the ream, from the Missouri Interstate Paper Co. Samples 1 inch square were taken from each corner of each sheet, dried in a desiccator, and weighed. The coefficient of variation was found to be 1.73. The areas corresponding to the various materials on the drawing were cut out with scissors, placed in separate envelopes, and dried in a desiccator over fused calcium chloride. It was found by test that they were brought to constant weight in fifteen hours. I n order to insure thorough drying, all paper was left in the desiccator for at least fortyeight hours. After drying, the paper corresponding to each material was weighed separately on an analytical balance sensitive to 0.1 mg. MICROSCOPIC STRKCTUBE The suprarenal glands of chickens have cortical and medullary material intimately mixed together. So far as could be estimated without measurement, the proportion is about the same in all parts of the gland, peripheral and central parts showing about the same percentage of cortex and medulla. The arrangement of cell masses, however, is different in central and peripheral portions and suggests that of the mammalian gland. I n all the glands of the chickens examined a glomerular zone resembling that of mammals in arrangement of cortical cells was distinguishable at the periphery, The central mass of the glands has an arrangement similar to that of the reticular zone in mammals. I n a few glands a radial arrangement of cell columns between the central reticular and peripheral glonierular zones is visible. It is to be noted that in mammals the arrangement described applies to cortex with no admixture of medulla, while that in the chicken applies to a mixture of the two kinds of cells. I n the peripheral part of the glands the cortical cells are arranged in columns and folded layers. The cortical cells in this region are elongated, with their long axes transverse to the plane of the column or layer. Cortical cells of the SEX DIFFERENCES IN THE CHICKEN SUPBARENAL 293 central part of the gland are arranged in clumps. Medullary cells in all parts of the gland have an irregularly rounded shape. RESULTS AND CONCLUSIONS The gross body weights, the weights of the right and left glands, and the proportions of the parts of the glands of the nineteen chickens are given in table 1. The average weight of the male glands is slightly greater than that of the female, but it does not form a larger percentage of body weight, because of the greater body weight of the males. The weights of the paper representing the various parts of the glands were recorded, but to save space these weights are not given. The weights of the glands and of the parts of the glands reduced to percentages of the gross body weights are given in table 2. The per cent of blood and extraneous materials is variable and not significant, since the clotting time of chicken blood is extremely subject to variation (Thompson and Carr, '23). The averages in table 2 seem to indicate a slightly heavier female suprarenal, but the small number of specimens does not warrant questioning the conclusion (Latimer, '24) that the weight of the suprarenal glands is approximately the same in the two sexes, since this difference is too small in proportion to the probable error to be considered significant. The average actual weight exceeded the average predicted weight (using the formula from above paper) by 1.7 per cent f o r the males and 9.5 per cent for the females. The procedure used permits direct calculation of the per cent which the suprarenal gland forms of the body weight of the chicken. It also gives percentages by volume of the various materials in the gland. I n order to know the percentages by weight which each material in the gland forms of the body weight of the chicken, it would be necessary to know percentages by weight, instead of by volume, of the materials in the gland. Since this cannot be determined, it is necessary to make an assumption as to the specific gravity of the component materials of the glands. The assumption was made F. C. SAUER A N D H. B. LATIMEE t-m 9t - m2 mt- 0 0 r-d w w a 0 cnm worn a m 10+ 0 0 0 0 0 0 0 0 0 0 d m 11 9 9 9 3 9 9 3 9 m o 0 0 1e 0 0 m o e w r i m a m 3 3 99 0 0 0 0 a 1%' iX SEX DIFFERENCES IN THE CHICKEN 295 SUPRARENAL that cortex and medulla are of the same specific gravity, and data of table 2 were calculated accordingly. The assumption cannot introduce any serious error, as it is applied to glands of both sexes. TABLE 2 Entire gland, cortex, and medulla as percentages of body weight 1 No, Entire gland Cortex Medulla .00247 .00276 Medulla - _ _ ~ . _ _ _ ~ ._ 1L 1R .0060 .0067 .00176 .00232 2L 2R' .0039 .0034 .00178 .00130 ...... 3L 3R .0033 .00,i3 4L 4R - 11R .0035 .00219 .00175 ...... 12L 12R .0069 .0073 .00281 .00308 ,00219 .00263 .do178 .00249 .00091 .00122 13L 13R .0038 .0034 .0014B .00183 .00119 .00088 .0043 .0038 .00251 .00219 .00105 .00122 14L 14R .0052 .0063 .00223 .00290 .00182 .00230 5L 5R .0032 .0024 .00186 .00155 .00082 .00061 l5L 15R .0062 .0037 .00238 .00189 .00113 .00086 6L 6R .0074 .!I068 .00179 .00195 .00251 .00318 16L 16R .0067 .0051 .00231 .00256 .00170 .00111 7L 7R .0058 .0054 .00257 .00273 .00156 .00174 17L 17R .0072 .0069 .00316 .00392 .00152 .00143 8L 8R .0071 .0049 .00245 .00212 .00241 .00163 18L 18R .0064 .0073 .00363 .00490 .00141 .00147 9L 9R .0047 .0061 .00251 .00237 .00144 .00171 19L 1SR .0054 .0056 .00320 .00359 .00084 .00091 ...... ...... .00129 _ _ .00211: .00006 ,00144 .00164? ,00012 .0073 10L' .0038 10R ~Average .00510: .00022 ~ ' Pathological, . Average I 1 ~- ~ .005733 .00020 .00204 .00071 -~ ~- .00276: .00014 .0014Ri. .00009 ~- .- not used. The difference between the mean percentage weights of the cortex in the two sexes is 0.00065, or a difference of 31 per cent of the smaller percentage. Using the formula given by Dunn ('29) for determination of the probable error of the difference, we have 0.00065 0.00015, or a probable error a little less than one-fourth the difference. While a larger 296 F. C. SAUER AND H. B. LATIMER ratio of difference t o probable error is t o be desired, the result would justify at least a tentative conclusion that the female domestic fowl actually has more cortex in proportion to body weight than the male. A larger number of specimens would permit a more definite conclusion. I n the male chickens the percentage which cortex forms of the body weight is less variable than either the gross weight of the gland or the per cent of cortex in the gland. The coefficients of variation are : cortex as per cent of body weight, 18.7; per cent of cortex in the gland, 25.5; and gross weight of suprarenal, 30.5. So far as the male glands are concerned, the weight of the cortex is fairly constant, and variations in the gross weight of the gland are due mainly to a variable amount of medulla. The male cortex as a per cent of body weight is less than half as variable as that of the female. The greater variation in the per cent of cortex in the female suggests that the amount of cortex may vary at different periods of ovulation. The standard deviation of the per cent of cortex is 0.00039 for males and 0.00086 for females. Nothing is known of the history of the birds, other than that they appeared to be in good health when they were killed. The most important conclusion to be drawn from this study is that which pertains to the relative amount of cortex, as a per cent of body weight. The result would indicate that chickens resemble mammals in having a larger per cent of cortex in the female, and it explains the correspondence of the gross weight of the suprarenal in the two sexes as being due to a smaller per cent of medulla, approximately offsetting the larger per cent of cortex, in the female. SUMMARY 1. The female chicken has approximately 30 per cent more suprarenal cortex, in proportion to its body weight, than the male, although the gross weight of the glands is about the same in the two sexes. 2. The amount of suprarenal cortex is much more variable in the female than in the male, suggesting a physiological variation. SEX DIFFERENCES IN THE CHICKEN SUPRARENAL 297 3. The suprarenal of the chicken shows a configuration of cell masses of mixed cortical and medullary material, suggesting in general appearance that of the cortical zone of mammals. 4. The weight of the suprarenal gland was not found to be significantly different on the two sides in either sex. BIBLIOGRAPHY DONALDSON, H. H. 1924 The rat. The Wistar Institute. J. C. 1919 Relative volumes of cortex and medulla in the adrenal DONALDSON, gland of the albino rat. Am. Jour. Anat., vol. 25, pp. 291-298. DUNN, HALBERTL. 1929 Application of statistical methods in physiology. Physiol. Rev., vol. 9, pp. 275-398. HATAI,S. 1913 On the weights of the abdominal and thoracic viscera, the sex glands, and the eyeballs of the albino r a t (Mus norvegicus albinus) according to the body weight. Am. Jour. Anat., vol. 15, pp. 87-120. HAYS,V. J. 1924 The development of the adrenal glands of birds. Anat. Rec., vol. 8, pp. 4 5 1 4 7 4 . HILL, W. C. 0. 1930 Observations on the growth of the suprarenal cortex. Jour. of Anat., vol. 64, pp. 479-502. JACKSON, C. 31. 1913 Postnatal growth and variability of the body and various organs in the albino rat. Am. Jour. Anat., vol. 15, pp. 1-68. 1917 Effects of inanition and refeeding upon the growth and structure of the hypophysis in the albino rat. Am. Jour. Anat., vol. 21, pp. 321-358. 1919 The postnatal development of the suprarenal gland-and the effect of inanition upon its growth and structure in the albino rat. Am. Jour. Anat., vol. 25, pp. 221-289. LATIMEEL, H. B. 1924 Postnatal growth of the body, systems and organs in the single comb white Leghorn chicken. Jour. Agri. Research, vol. 29, pp. 363-397. 1925 The relative postnatal growth of the systems and organs of the chicken. Anat. Rec., vol. 31, pp. 233-253. 1927 Correlations of the weights and lengths of the body, systems, and various organs of the turkey hen. Anat. Rec., vol. 35, pp. 365-377. LATIMER,H. B., AND J. A. ROSENBAUM1926 A quantitative study of the anatomy of the turkey hen. Anat. Rec., vol. 34, pp. 15-23. PANKRATZ, D. S. 1931 The development of the suprarenal gland of the albino rat, with a consideration of its possible relation t o the origin of fetal movements. Anat. Rec., vol. 49, pp. 31-50. RASMUSSEN,ANDREWT. 1928 The weight of the principal components of the normal male adult human hypophysis cerebri. Am. Jour. Anat., vol. 42, pp. 1-27. SCAMMON, R. E., A N D G. H. SCOTT 1 9 i 7 The technique of determining irregular areas in morphological studies. Anat. Rec., vol. 35, pp. 269-277. 298 F. C. SAUER AND H. B. LATIMER THOMPSON,T. J., AND I. L. CARR 1923 The relation of certain blood constituents to a deficient diet. Biochem. Jour., vol. 17, pp. 373-375. VINCENT, SWALE 1912 Internal secretion and the ductless glands. Edward Arnold.