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D Jacob

Publications and source records attributed to D Jacob.

32 records · Page 2Linked to original sources
PubMed1975

Effect of sex steroids on the male reproductive organs of the monitor lizard Varanus monitor (Linn.).

Exogenous sex steroids were administered to adult males of the monitor lizard Varanus during the retrogressive and inactive phases of their annual reproductive cycle. Androgen treatment renews spermatogenetic activity and causes an increase in the number of Leydig cells of the testis during the retrogressive phase; during the inactive phase the testicular response to androgen is only slight. In either reproductive phase oestradiol treatment has an inhibitory action on the germ tubules. Progesterone has no effect on the testis in the inactive phase. The vasa deferentia are well developed during the retrogressive phase and thus the effect of androgens is not appreciable. However, during the inactive phase testosterone highly stimulates the deferent ducts. In the inactive phase oestrogen and progesterone also seem to stimulate slightly the deferent tubules; progesterone increases the interstitial tissue of the deferent ducts. Renal sexual segments hypertrophy and become secretory by androgen treatment in either phase of the reproductive cycle, whereas oestrogen and progesterone have no effect. The hemipenes are also stimulated by androgen treatment.

Animals↗
PubMedDate not supplied

Inhibition of fertility in the male mouse by combined androgen-antiandrogen therapy.

Testosterone enanthate (TE) and oestradiol valerate (EV) in varying dose combinations were subcutaneously injected every alternate day for 10 or 20 days to adult male mouse of proven fertility. Such therapy resulted in suppression of fertility without affecting libido. The main possible cause of fertility inhibition appears to be testicular dysfunction as evidenced by histology and biochemistry of the reproductive organs.

Animals↗