Effects of castration and/or hypophysectomy on the seminal vesicles of the catfish, heteropneustes fossilis (Bloch)

Abstract

The response of the seminal vesicles to hypophysectomy and/or castration during the prespawning and the spawning periods was studied. Forty days post-hypophysectomy the seminal vesicles regress completely, whereas 40 days postcastration they show hyperactivity which is accentuated by 85 days post-surgery. Further, catfish castrated i n the prespawning period of 1966 not only show hyperactive seminal vesicles i n that season but also exhibit hypersecretory seminal vesicles in the following breeding season, in spite of the absence of the testes, In the castrate catfish, hyperactivity i n the seminal vesicles is accompanied by a significant increase in the number and activity of the granulated basophils in the pituitary and an increase in the nuclear diameter of the interrenal cortical cells, Two hypotheses are proposed to explain this paradoxicsl phenomenon.

Seasonal changes in steroid metabolism in the male reproductive organ-system of the African catfish, Clarias gariepinus

“…This hormone together with the testicular androgens may stimulate secondary sex characters and spawning behaviour, and -contrary to the nonaromatizable 11-oxygenated androgens -stimulate gonadotropin synthesis in the pituitary, as demonstrated by De and Van Oordt et al (1987). The androgens produced by the seminal vesicle might also induce secretory activity of the seminal vesicle epithelium, as suggested by Sundararaj and Nayyar (1969) …”

Seminal vesicle and its role in the reproduction of teleosts

“…Further, experimental studies using castration and anti-androgen treatment have corroborated the importance of androgens in stimulating SV activity (Sundararaj and Nayyar 1969c;Singh and Joy 1998b;Chowdhury andJoy 2000a, 2001b). Interestingly, castration produced a paradoxical effect of hypertrophy and hyperactivity in the SV of catfishes (Sundararaj and Nayyar 1969b;van Weerd 1990;Singh and Joy 1998b;Chowdhury and Joy 2001b, c), which can be suppressed by anti-androgen treatment (Sundararaj and Nayyar 1969c;Senthilkumaran and Joy 1993;Singh and Joy 1998a;Chowdhury and Joy 2001b). This paradoxical effect of castration is explained by two hypotheses (Sundararaj and Nayyar 1969b).…”

“…Interestingly, castration produced a paradoxical effect of hypertrophy and hyperactivity in the SV of catfishes (Sundararaj and Nayyar 1969b;van Weerd 1990;Singh and Joy 1998b;Chowdhury and Joy 2001b, c), which can be suppressed by anti-androgen treatment (Sundararaj and Nayyar 1969c;Senthilkumaran and Joy 1993;Singh and Joy 1998a;Chowdhury and Joy 2001b). This paradoxical effect of castration is explained by two hypotheses (Sundararaj and Nayyar 1969b). The low titre of androgens activates, through negative feedback, gonadotropin and other pituitary hormone secretions, which act on the SV epithelial cells directly or indirectly through the interstitial cells.…”

The seminal vesicle as source of sex attracting substances in the African catfish, Clarias gariepinus

“…Enlargement of the seminal vesicle after castration in the catfish Heteropneustes fossilis (Sundararaj and Nayyar, 1969) led the authors to suggest that this castration effect might be due to stimulation by gonadotropin. Castration in Clurius garipienus indeed results in a rise of circulating GTH, which is followed by a decline within 2 weeks of surgery .…”