Leydig Cell Hypertrophy Research Articles

Effects of experimental torsion of the spermatic cord on Leydig cell function in the guinea pig testis: an ultrastructural stereological analysis.

An ultrastructural stereological analysis of Leydig cells of the guinea pig testis was carried out following surgically induced testicular torsion. Morphometric analyses of the Leydig cells of the experimental group of animals revealed an increase in the nuclear and mitochondrial volume and a decrease in the lipid volume, in comparison to those in the Leydig cells of the control group of animals. We believe that these changes in the Leydig cells of the experimental group of animals are indicative of cellular hypertrophy. The possible mechanisms of the Leydig cell hypertrophy in the guinea pig testis following the induction of spermatic cord torsion are discussed.

Quantitative and ultrastructural study of Leydig cells in Klinefelter's syndrome.

This ultrastructural and quantitative study of Leydig cells in Klinefelter's syndrome has been performed using the entire testes obtained from four autopsies plus testicular biopsies from 20 patients. The total Leydig cell volume per testis in Klinefelter's syndrome was similar to that of control testes. However, the total number of Leydig cells per testis was significantly lower in the patients with Klinefelter's syndrome than in the controls. This may be attributed to the Leydig cell hypertrophy that these patients underwent. In patients with Klinefelter's syndrome the average volume of each Leydig cell was significantly higher than that of the controls. Electron microscopic findings revealed that besides ultrastructurally normal Leydig cells there were three other morphologically abnormal Leydig cell types: abnormally differentiated cells; multivacuolated cells; and immature Leydig cells. The ultrastructurally normal Leydig cells were probably the cells principally responsible for testosterone biosynthesis in these patients, whereas the other Leydig cell types were probably barely or not at all functional. The hypertrophy showed by the ultrastructurally normal Leydig cells may be interpreted as an attempt to increase testosterone production.

Follicle-stimulating hormone induction of Leydig cell maturation.

The effects of FSH on the testes of immature hypophysectomized rats were investigated by comparing functional changes in Leydig cells with changes in their number and morphological appearance. Rats were treated twice daily for 7 days with 0.5 ml saline vehicle, 10 micrograms rat FSH, or 20 ng ovine LH (an equivalent amount of LH known to contaminate the FSH preparation). FSH treatment caused a significant increase in testis weight and stimulated more advanced spermatogenic activity compared to saline or LH treatment. Morphometric analysis of glutaraldehyde perfusion-fixed testes showed no significant increase in Leydig cell number after LH treatment [saline, 4.63 +/- 0.14 million cells; LH, 6.38 +/- 0.55 million mean +/- SE)], but a significant (P less than 0.001) increase after FSH treatment (11.55 +/- 0.79 million). FSH, but not LH or saline, treatment resulted in Leydig cell hypertrophy and ultrastructural features identical to those of adult Leydig cells, these changes being reflected by enhanced hCG- and LHRH agonist-stimulated testosterone production in vitro by whole testes or dispersed interstitial cells. FSH and LH treatment caused minor but significant decreases in LH receptor numbers on dispersed interstitial cells compared to saline treatment. LHRH receptor numbers on interstitial cells were significantly increased only by FSH treatment. It is suggested that since FSH acts only on the seminiferous epithelium, then the hypertrophy, hyperplasia, and functional enhancement of Leydig cells after FSH treatment may be mediated by the secretion of one or more factors from the seminiferous tubules, providing additional evidence to support the view that gonadotropic regulation of testicular function is modulated by local interactions between the seminiferous tubules and the interstitial tissue.

Evaluation of Leydig cell function and gonadotropin binding in unilateral and bilateral cryptorchidism; evidence for local control of Leydig cell function by the seminiferous tubule.

The Leydig cell hypertrophy and loss of LU receptors that accompanies the surgical induction of bilateral cryptorchidism has been attributed to elevated serum LH levels. This study demonstrates that in unilaterally cryptorchid rats, the Leydig cell hypertrophy and loss of LH receptors is confined to the abdominal testis and there is no significant change in these parameters in the scrotal testis.These resultsand the failureof serum L.H levelsto increase following unilateral cryptorchidism until4 weeks, indicate that local factors within the cryptorchid testis must result in the changes in Leydig cell function. In addition to the loss of LU receptors and Leydig cell hypertrophy, the cryptorchid testis showed a hyperresponsive testosterone response to hCG stimulation in vitro and a loss of FSH receptors whereas both of these parameters were normal in scrotal testes of the unilaterally cryptorchid rats.

Effects of α-Chlorohydrin on the Testes and Epididymides of Dog: A Preliminary Study

Chronic administration of alpha-chlorohydrin (8 mg/kg for 30 days, caused lesions in the testis of dog. Seminiferous tubules presented marked degenerative changes. Leydig cell hypertrophy was conspicous. Epididymal epithelium was regressed and the lumen was devoid of spermatozoa. Obstruction of the epididymal lumen was not seen. Alpha-Chlorohydrin inhibited the synthesis of RNA and sialic acid in the testis, caput epidiymis, corpus epididymis, and cauda epididymis. The total cholesterol per gram of testis was increased significantly after alpha-chlorohydrin administration. The anti-androgenic nature of alpha-chlorohydrin is suggested.

Changes in testicular leydig cells and in plasma testosterone levels among seasonally breeding rock hyrax.

Seasonal changes in plasma testosterone levels and in various testicular parameters were studied in 41 adult male rock hyrax (Procavia habessinica). Among animals collected during the annual breeding season, testis weights and plasma testosterone levels were approximately five times greater than among animals collected outside the breeding season. Light microscopic measurements showed that increase in testis weight was largely due to enlargement of the seminiferous tubules. Histological sampling techniques indicated no significant change in Leydig cell numbers. Leydig cell size increased during the breeding season, and average Leydig cell volume showed significantly positive correlation with plasma testosterone level. With the electron microscope, Leydig cell hypertrophy was seen to involve changes in quantity and structure of several cytoplasmic constituents. Lipid droplets disappeared and smooth endoplasmic reticulum (SER) spread dramatically as the cells increased in size. In contrast to the sparse and heterogeneous assemblage of irregularly tubular and cisternal SER seen in nonbreeding animals, the extensive masses of SER in breeding animals appeared as relatively straight, unbranched tubules of uniform diameter. Peculiar membranous structures, possibly derived from the SER, were abundant in the periphery of Leydig cells from animals with high plasma testosterone levels. These findings suggest that there is a definite relationship between plasma testosterone levels and Leydig cell fine structure in seasonally breeding hyrax.