Effects of exogenous gonadotrophins and gonadal hormones on the testes and seminal vesicles of hypophysectomized catfish, Heteropneustes fossilis (Bloch)

Sundararaj, Bangalore I.; Nayyar, S. K.

doi:10.1016/s0016-6480(67)80003-0

Cited by 62 publications

(16 citation statements)

References 18 publications

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“…The putative effects of 11-KT on spermatogenesis in black porgy were consistent with those in gonochoristic teleosts (Sundararaj and Nayyar 1967;Pandey 1969;Billard 1978;Miura et al 1991a;Cochran 1992). Plasma levels of 1l-KT, but not T, were also closely associated with the milt volume in black porgy; milt volume increased without affecting sperm concentrations during testicular development.…”

Section: Discussionsupporting

confidence: 70%

“…Estradiol-1715 (E 2 ), testosterone (T) and 11-ketotestosterone (11-KT) have received the most attention; T and 11-KT appear to be involved in spermatogenesis and spermiation (Sundararaj and Nayyar 1967;Hansson et al 1976;Cochran 1992), while E 2 induces vitellogenesis synthesis and oocyte development (de Vlaming et al 1980;Kishida et al 1992). There is less information on the gonadal development and its relation to endocrine data in the protandrous male black porgy.…”

Section: Introductionmentioning

confidence: 99%

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Estradiol-17? suppresses testicular development and stimulates sex reversal in protandrous black porgy, Acanthopagrus schlegeli

Chang

Lau

Lin

1995

Fish Physiol Biochem

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Two year old black porgy (Acanthopagrus schlegeli) fed a diet containing 4.0 mg kg(-1) of estradiol-17β (E2) for 5 months had significantly lower GSI than the control group during the spawning season. E2 suppressed testicular development, spermiation and plasma testosterone (T) and 11-ketotestosterone (11-KT) and stimulated ovarian development, vitellogenesis and sex reversal. Spermiation in the control group occurred in January and February with the concentrations of 1.08-1.36 × 10(10) sperm ml(-1) of milt. Higher plasma T and 11-KT, but lower E2 levels were detected in the spermiating fish (control group). Higher plasma E2 levels were detected in the sex reversing black porgy during the pre-spawning season. A sharp rise in plasma 11-KT and a drop in T levels were detected in spermiating fish (control group) from January to February. Plasma 11-KT levels correlated with the testicular development and spermiation. The data suggest that E2 plays an important role in controlling the sex reversal of black porgy.

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Section: Discussionsupporting

confidence: 70%

Section: Introductionmentioning

confidence: 99%

Estradiol-17? suppresses testicular development and stimulates sex reversal in protandrous black porgy, Acanthopagrus schlegeli

Chang

Lau

Lin

1995

Fish Physiol Biochem

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“…Apparently, this limited rise in GTH output was sufficient for the growth of testes and seminal vesicles. Regulation of these processes by gonadotropin has been demonstrated for Heteropneustes fossilis (Sundararaj and Nayyar, 1967;Sundararaj et al, 1971;Nayyar et al, 1976). In this catfish species, hypophysectomy resulted in regression of testes and seminal vesicles; replacement therapy with gonadotropins appeared to restore their functional activity.…”

Section: Discussionmentioning

confidence: 89%

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

et al. 1987

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In testes, the capacity to form progestins, androgens, especially ll-oxygenated ones, and steroid glucuronides increased enormously in the periods of full spermatogenesis and breediig, with 5#?-pregnane-3a,17a,20a-triol and 5fi-pregnane-3a,17t-diol-20-one glucuronide as the main polar products. In the same periods, seminal vesicles are able to form ll-oxygenated androgens from[ 3H] -androstenedione and show an increased capacity to form testosterone. Their ability to produce testosterone glucuronide is strongly enhanced in the period of full spermatogenesis and further increases in the breeding period. In this latter period, the capacity to form 5/$androstane3a,l7cr-diol glucuronide is also stimulated. The function of the main steroids and steroid glucuronides is discussed, with special reference to the water-soluble compounds that may serve as sex pheromones.

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“…the Blennidae, Gobiidae (Eggert, 1931;Weisel, 1949)) Ictaluridae (Sneed and Clemens, 1963 ) and Siluridae ( Van Tienhoven, 1983 ) , the male gonads are composed of two separate organs, the testes and the seminal vesicles. In the Siluridae, histological and enzyme-cytochemical investigations of the Indian catfish, Heteropneustes fossilis (Sundararaj and Nayyar, 1967;Nayyar and Sundararaj, 1969), and the African catfish (Resink et al, 1987c;Van Den Hurk et al, 1987a) point to interstitial cells in the seminal vesicles as well as the testes as possible sources of steroids.…”

Section: Introductionmentioning

confidence: 99%

Steroidogenesis in the testes and seminal vesicles of spawning and non-spawning African catfish, Clarias gariepinus

et al. 1987

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The in vitro biosynthesis of steroids was studied in testes as well as seminal vesicles of nonspawning pond and spawning feral African catfish, collected during the breeding season. In testes of non-spawners the conversion of [3H]-pregnenolone was directed towards 11-oxygenated androgens and 5j?-pregnane-3cu,l7cu,20cz-triol, whereas in testes of spawners the production of progesterone and 17&-hydroxyprogesterone prevailed. The seminal vesicles, on the other hand, produced mainly pregnenolone ester, androstenedione and testosterone in non-spawning catfish and 5@educed steroids in spawning catfish. Furthermore, in these seminal vesicles, steroid glucuronide synthesis dominated much more than in testes. There was, however, no difference in synthesizing capacity between the two groups. Spawning was accompanied by elevated plasma gonadotropin levels.

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Effects of exogenous gonadotrophins and gonadal hormones on the testes and seminal vesicles of hypophysectomized catfish, Heteropneustes fossilis (Bloch)

Cited by 62 publications

References 18 publications

Estradiol-17? suppresses testicular development and stimulates sex reversal in protandrous black porgy, Acanthopagrus schlegeli

Estradiol-17? suppresses testicular development and stimulates sex reversal in protandrous black porgy, Acanthopagrus schlegeli

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

Steroidogenesis in the testes and seminal vesicles of spawning and non-spawning African catfish, Clarias gariepinus

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