Studies on Testicular Function III. Effects of FSH, LH, Testosterone and Dihydrotestosterone on Restoration and Maintenance of Testicular-Specific Lactate Dehydrogenase Activity in the Hypophysectomized Rat

Abstract

Hypophysectomy of the adult male rat depressed the activity of testicular-specific lactate dehydrogenase (LDH-X). Groups of rats were treated with FSH (F), LH (L) or testosterone (T) alone or in combination after 32 days of post-hypophysectomy regression (restoration experiment) for a further 32 days or with F, T or dihydrotestosterone (D) alone or in combination from 2 days after hypophysectomy (maintenance experiment) for 30 days.LDH-X activity per milligram of protein was restored to normal by the hormonal combinations FT and LT while F, L, or T given alone or the FL and FLT combinations were ineffective. However, the total LDH-X activity per testis was only partially restored by the hormonal combinations FT, LT and FLT.In the maintenance experiment LDH-X activity per milligram of protein was maintained by all hormonal treatments except D, while the total LDH-X activity per testis was completely maintained by the FT hormonal combination. All other hormonal treatments except F alone maintained the activity of this isoenzyme above the level in the hypophysectomized rat.The restoration and maintenance of LDH-X activity in the testis of the hypophysectomized rat was successful with those combinations of hormones that were also able to restore or maintain the numbers of late primary spermatocytes and spermatids. Thus, the level of LDH-X activity in the testis is dependent on the presence of late primary spermatocytes and spermatids and hence this enzyme is a good marker for the production of these cells in the rat testis.

Comparative Study Of Artesunate, ACTs And Their Combinants On The Spermatic Parameters Of The Male Guinea-Pig

“…The effects were also more pronounced at the subclinical doses of the agents, which points out that the hormonal effects of these agents are positively correlated with their effects on sperm parameters. This is in agreement with the reports of Elkington and Blackshaw, (1974) and Ganong, (2001) The effects observed in this study may be due to damages to the Leydig cells and seminiferous tubules responsible for testosterone and sperm productions respectively. Damage to Leydig cells will result in decreased testosterone production, which will in turn decrease spermatogenesis.…”

Androgen receptor function is required in Sertoli cells for the terminal differentiation of haploid spermatids

“…After long-term Hx and elimination of residual testosterone by flutamide, spermatogenesis rarely proceeds beyond meiosis, with very few round spermatids observed and elongated spermatids nearly nonexistent (Franca et al, 1998). As with Gnrh-null mice, androgen or LH replacement leads to qualitative recovery of spermatogenesis in hypophysectomized rats while FSH has little direct stimulatory effect on spermatogenesis (El Shennawy et al, 1998;Elkington and Blackshaw, 1974;Russell and Clermont, 1977). Similar results are seen in response to suppression of Gnrh activity (Szende et al, 1990), and destruction of Leydig cells with the Leydig-specific cytotoxin EDS (Kerr et al, 1993;Sharpe et al, 1990).…”

Comparative study of artesunate, acts and their combinants on the hormonal parameters of the male guinea-pig

“…Spermatogenesis is the process of transformation of male germ cells into spermatozoa and requires high intratesticular levels of testosterone, produced by the Leydig cells (Ganong, 2001). Furthermore, the synthesis of testosterone is influenced by LH, Prolactin and FSH (Elkington and Blackshaw, 1974).…”