Morphometric Studies in the Leydig Cell of Hemicastrated Rats / 체질인류학회지

The present study was conducted to investigate the influence of hemicastration and age at hemicastraion on the subsequent Leydig cell morphology and function of male rats. Sprague Dawley rats were left intact or hemicastrated at 20, 30, 40, 50, or 60 days of age (n=18 rats per group). At 100 days of age, all rats were sacrificed. Testes were fixed by whole body perfusion using a fixative containing 2.5% glutaraldehyde in cacodylate buffer, processed and embedded in Epon-araldite. Using 1 micrometer sections stained with methylene blue, qualitative and quantitative morphological studies were performed. Testis incubations were used to determine lutenizing hormone (LH; 100 ng/mL) stimulated testosterone secretory capacity per testis in vitro. Testosterone levels in the incubation medium, and testosterone and LH levels in serum of these six groups of rats were determined by radioimmunoassay. Body and testis weights were not changed by hemicastration between experimental and control groups. Volume density of seminiferous tubules, interstitium, and Leydig cells was not significantly affected by hemicastration. Absolute volume of seminiferous and interstitium was significantly increased in unilaterally castrated rats at 20, 30 and 40 days of age compared to control. Significant increases in the total number of Leydig cells per testis occurred in rats hemicastrated at 20, 30, 40 and 50 days of age compared to control. A significant increase in average volume of a Leydig cell was noted in the hemicastrated rats at 30 and 40 days compared to intact rats of the same age but was significantly decreased at 60 days of age. Serum testosterone levels and LH-stimulated testosterone production per testis were significantly (P<0.05) increased in the hemicastrated rats at 30 and 40 days. In summary, when rats were unilaterally castrated at 20, 30, 40, 50, and 60 days of age, those rats hemicastrated at 30 and 40 days showed compensatory hypertrophy/hypersecretion of Leydig cells when killed at 100 days of age. Especially, these data suggested that compensatory hypertrophy/hypersecretion of Leydig cells in rats hemicastrated around the time of puberty occurs in the remaining testis.

The Effect of Myocardial Infarction on the Reproductive Function in Adult Male Rats / 체질인류학회지

The present study was to investigate in more detail the changes of reproductive function in the male rat following myocardial infarction (MI). Ligation of the left coronary artery was performed in male Sprague-Dawley male rats at 60 days of age. Control rats were obtained sham-operated animals. MI rats were sacrificed at 1, 3, 5, 7, 14, and 30 day after ligation of left anterior descending coronary artery. Control rats were sacrificed on 30 day after thoracotomy. Myocardial infarct size was assessed by planimetry and perimetry. Testes of rats were fixed by whole body perfusion using a fixative containing 2.5% glutaraldehyde in cacodylate buffer, processed and embedded in Epon-araldite. Using 1 micro sections stained with methylene blue-azure II, qualitative and quantitative (stereological) morphological studies were performed. Testosterone levels in the incubation medium of luteinizing hormone-stimulated (100 ng/mL) testosterone secretion per testis in vitro, and in serum were determined by radioimmunoassay. Sperm production was measured by routine technique. Mean infarct size was 29.5~33.5% of the left ventricle after coronary occlusion in experimental groups. No changes were observed in testis volume, absolute volume of Leydig cell, Leydig cell size, and number of Leydig cell per testis in MI rats compared to sham-operated animals. Serum testosterone, LH-stimulated testicular testosterone production, and daily sperm production in MI rats were not significantly different (P>0.05) from sham-operated animals. These results demonstrate that under the experimental conditions employed here, experimental chronic myocardial infarction does not exert adverse effects on the reproductive function of male rats.

Effects of Luteinizing and Thyroid Hormones on the Aged Leydig Cells in Brown Norway Rats / 체질인류학회지

ABSTRACT: The present study was designed to investigate the possibility of restoring the testicular steroidogenic ability of the aged Brown Norway rats by administering luteinizing hormone (LH) and thyroxine (Thy). Rats of 3, 6, 12 months (M) of age (n = 8 per group) and four groups of 18 month old rats (n = 8 per group) were used. Eighteen month old rats were implanted subdermally with Alzet mini osmotic pumps containing saline (control), luteinizing hormone (LH, 24 microgram/day), thyroxine (Thy, 5 microgram/day) and LH and Thy (LH +Thy, 24 microgramday and 5 microgram/day), respectively for four weeks (i.e testing was done at 19 months). The results showed that the testis volume was unchanged among all treatment groups. The number of Leydig cell per testis was not significantly different among all treatment groups. The average volume of a Leydig cell was significantly decreased at 12 months, and a further reduction was observed at 19 months (saline-treated); values for 19 month LH-and-LH +Thy-treated rats were not significantly lower than those at 3 and 6 months of age. Testosterone secretory capacity per testis and per Leydig cell in vitro were significantly reduced concomitantly with age advancement from 6 to 19 months (saline-treated) of age. These values of LH-and Thy-treated 19 month old rats were similar to those at 12 months. LH +Thy-treated rats were equally capable to 3 and 6 month old rats in producing testicular testosterone in vitro in response to LH. Serum testosterone was unchanged from 3 M to 12 M rats but was reduced in 19M control rats. Both LH and Thy significantly raised these values above the 19M control levels, but they were still lower than the 3 M through 12 M levels. Additionally, LH +Thy significantly raised the serum testosterone levels to those of 12M rats, but these values were significantly lower than those of 3 M and 6 M rats. In summary, the present study demonstrated that the exogenous supplementation of LH and Thy was effective in restoring the steroidogenic potential of the aged Leydig cells; the most effective treatment was LH +Thy, which upgraded the capacity of aged testes to those of 3 and 6 months.

Continuous Exposure of Lactating Rat Mothers to Polychlorinated Biphenyls (PCBs) Increases Testis Volume, Sperm Production and Sertoli Cell Numbers in Adult Male Offspring / 체질인류학회지

Despite the possible consequences of maternal ingestion of polychlorinated biphenyls (PCBs) on future generation, information in limited on how/whether maternal PCB exposure affects testis of the adult male offspring. Therefore, we conducted two experiments to investigate the effects of intermittent and continuous of lactating rats to low and high doses of Aroclor 1242 (a PCB congener) on volume density of seminiferous tubules and interstitium, testis volume, sperm production/day and the total number of Sertoli cells per testis in adult male offspring. In experiment I, 3 groups of lactating Sprague Dawley rats received daily subcutaneous injections of 0.1 ml of corn oil, low dose (8microgram) and high dose (80microgram) of Aroclor 1242 in corn oil respectively, from parturition to weaning of pups at 21 days. In experiment II, 3 groups of lactating rats received 2 subcutaneous injections per week of 0.1 ml corn oil, low and high doses of Aroclor respectively, as in experiment I. Pups in all groups were weaned at day 21 and were raised on a normal diet until sacrificed at 90 days to evaluate volume density of seminiferous tubules and interstitium, testis volume, sperm production/day and the total number of Sertoli cells per testis. Volume density of seminiferous tubules and interstitium per testis was determined by point counting method. Testis volume and sperm production/day was measured by routine techniques. The total number of Sertoli cells per testis was determined by morphometry(disector method). In experiment I and II, the volume density of seminiferous tubules and interstitium per testis was equal in control and treated testes. In experiment I (continuous exposure), the testis volume was increased by 14.8% (low dose)~16.5% (high dose), and sperm production/day and Sertoli cell numbers were increased 20.4~25%, and 32.6~39.4%, respectively. In experiment II (intermittent exposure), testis volume, sperm production/day and the total number of Sertoli cells per testis were not significantly different (p>0.05) in PCB-exposed rats (both low and high doses) compared to controls. It is clear that continuous exposure, but not intermittent exposure of male rats to Aroclor during the neonatalprepubertal period causes detrimental effects on the testis in adult male offspring. These results emphasize the susceptibility of the developing testis to environmental factors during the crucial neonatal period.

Morphometric Study of the Testicular Interstitium of the Rat during Postnatal Development / 대한해부학회지

The purpose of this morphometric study was to obtain quantitative information on the rat testis interstitium during postnatal development. Eight groups of male rats aged 1, 7, 14, 21, 28, 40, 60 and 90 days (n=5 rats per group) after birth were used. Tissue from perfusion-fixed testes was embedded in Epon-Araldite; and sections were subjected to morphometric measurements at the light microscopic level, using point counting method for volume densities and the Disector technique for numerical densities (the number of cells per unit volume of testis). The volume density of the interstitium represents 66% of the testicular parenchyma at day 1. This proportion progressively diminishes during development to reach a value of 8% at day 90. The absolute volume of blood vessels, macrophages, and endothelial cells increased with age. The absolute volume of lymphatic spaces, pericytes and myoid cells were greater at 90 days than at any other age. The absolute volume of fetal Leydig cells per testis was unchanged from 1 (0.07 mm3) to 14 (0.1 mm3) days, despite a decrease in the volume density. The number of mesenchymal cells, myoid cells, macrophages, endothelial cells, and pericytes per testis increased with age. The number of fetal Leydig cells per testis did not change from days 1 (0.054 million)~21 (0.070 million) although on day 21 (615 micrometer3) an average fetal Leydig cells was smaller in volume than at earlier ages (days 1 (1338 micrometer3)~14 (1296 micrometer3)). Adult Leydig cells were recognized at day 14 and their absolute volume and number per testis increased from 14 (0.5 mm3, 0.6 million) to 90 (52.83 mm3, 21.14 million) days. The average volume of a adult Leydig cell increased significantly with age and reached maximum size by 60 days (2548 micrometer3) of age where the volume is nearly three times bigger than that of at day 14 (832 micrometer3). No change in the average volume of the macrophages could be detected in this study groups. The average volume of the mesenchymal cells decreased significantly from day 1 (812 micrometer3) to day 14 (385 micrometer3) then increased until day 28 (901 micrometer3) at which the volume is maximum and declined significantly thereafter.

Studies on the Seasonal Changes in Epithelium of the Seminiferous Tubules and Serum Concentration of Testosterone , LH and FSH in the Korean Pheasant Phasianus colchicus / 대한해부학회지

It is highly desirable to achieve optimal reproductive performance, reliable morphological and physiological basic data of the reproductive organs. Therefore, seasonal changes in serum testosterone, LH, and FSH concentrations, and morphological changes in testicular epithelial cells were studied in the Korean native pheasant throughout the annual cycle. Mature male pheasants[14-16 months after hatching] were used in this study. The general morphological changes of the epithelia of the seminiferous tubules were observed by dibasic stain, and semithin section from Epon blocks with a phase contrast microscopy. The ultrastructural changes of the the epithelia of the seminiferous tubules were investigated by ultrathin section with transmission electron microscope. The changes in the profiles of the serum FSH, LH, and testosterone concentratioins were measured by RIA[radioimmunoassay]. The results obtained are summarized as follows : 1. There was little variation in the average diameter of the seminiferous tubules from autumn[67.13+/-5.95micrometer] to winter[68.59+/-6.07micrometer], but the highest levels were reached in spring[192.78+/-41.58micrometer]. Thereafter, the diameter decreased slowly in summer[146.57+/-43.68micrometer], then decreased significantly in autumn[67.13+/-5.95micrometer]. 2. Serum testosterne concentration was low from autumn[13.+/-7.21ng/100ml] to winter[17.39+/-13.75ng/100ml], but the highest levels were reached in spring[127.72+/-66.47 ng/100ml]. Thereafter, the concentration was lowest in autumn[13.+/-7.21ng/100ml]. 3. Serum LH concentration increased slowly and linealy from autumn[5.04+/-1.04ng/100ml] to winter[6.23+/-1.08ng/100ml], but the highest levels were reached in spring[11.3+/-3.6 ng/100ml]. Thereafter, the concentration reached the lowest level in autumn[5.04+/-1.04 ng/100ml]. 4. Serum FSH concentration was low from autumn[4.65+/-0.63ng/100ml] to winter[4.2+/-0.98ng/100ml], but the highest levels were reached in spring[17.41+/-8.35ng/100ml]. Thereafter, concentration was the lowest in autumn[4.65+/-0.63ng/100ml]. 5. The seminiferous tubules showed the onset of the spermatongenic cycle in spring but the seminiferous tubules collected in summer exhibited partially degenerative changes. 6. The cytoplasmic process of Sertoli cells of the seminiferous tubules of the pheasant were collected in summer. Many vesicles and degeneratiye changes were included but many number of spermatozoa were embedded partially in the multivesicular bodies in these processes. 7. The diameter of the seminiferous tubules of the pheasant narrowed markedly in autumn, and atrophied in winter. The spermatogonia and Sertoli cells were arranged in monolayer. 8. The myelin figures in the cytoplasmic process of Sertoli cells of the seminiferous tubules of the pheasant in autumn. The nucleus of the Sertoli cells were of a round configuration elongated and oriented perpendicularly to the basement membrane. The results obtained provide basic data for reproductive physiology and are useful for studying the male genital organs of the Korean native pheasant. Structural changes of the seminiferous epithelial cells significantly and postively correlated with serum FSH, LH. The correlation of changes in the hormonal status with alterations of Sertoli cell organells precedes the breeding season.