Dependence of Testicular Germ Cells on Hormones: A Quantitative Study in Hypophysectomized Testosterone-Treated Rats

Abstract

Quantitative analysis of spermatogenesis was used to investigate the dependence of testicular germ cells on hormones in Sprague-Dawley rats. Adult hypophysectomized rats were given daily injections of testosterone propionate (TP) for 30 days. Intact and hypophysectomized control rats received vehicle only. Spermatogonia were classified as undifferentiated or differentiated, using established criteria suitable for morphological identification on periodic acid-Schiff's-haematoxylin stained sections of testis. Data on cell counts showed that the undifferentiated spermatogonia may be partially dependent on TP and/or pituitary hormones. The group of differentiated spermatogonia were dependent on pituitary hormones, and TP only partially restored their number by partially protecting them from spontaneous degeneration in stages XIV to II (A3-to-Intermediate). The maturation and division of B type spermatogonia and maturation of preleptotene spermatocytes to the zygotene stage appeared to be independent of hormones. Maturation of pachytene spermatocytes was hormone dependent, and TP completely supported their development, meiotic division and spermiogenesis in the complete absence of pituitary hormones.

The effect of coadministration of α-tocopherol and ascorbic acid on arsenic trioxide-induced testicular toxicity in adult rats

“…The spermatogenic inhibition may occur in low levels of plasma gonadotropins and testosterone, the prime regulators of spermatogenesis in rats [32]. Our results also confirm this inhibition, which is correlated with diminution in the plasma level of testosterone and subsequently with the reduced activities of the testicular Δ 5 , 3β-HSD and 17β-HSD, the key steroidogenic enzymes [33].…”

Quantitative Cytological Studies of Spermatogenesis in Intact and Hypophysectomized Rats: Identification of Androgen-Dependent Stages*

“…The difference between these views resides in the lack of quantitative data on germ cell numbers in different endocrinological states available at the time of the earlier review. Although this process is testosterone dependent, it is important to note that the levels of testosterone required within the testis are only 10-15% of those in normal testis; as described previously by us (16) and others (12,(40)(41)(42)(43), spermiogenesis can be supported with considerably lower intratesticular testosterone levels than those observed in normal rats.…”

Scrotal Ultrasound in Male Infertility

“…The aim of the study was to verify the effectiveness of combined treat ment by evaluating the degree of damage to spermato genesis -a known androgen-dependent process [13,14] -and to monitor testicular changes in relation to the duration of therapy.…”