Posts Tagged ‘Growth Hormone

Testicular membrane preparations were obtained as previously described by Le Gac et al. . Briefly, testes were homogenized as described above in homogenization buffer containing 0.3 M sucrose and inhibitors of proteolytic enzymes and were centrifuged at 600 X g for 30 min in order to eliminate undisrupted tissue and cell nuclei. The supernatant was […]

Testicular membrane preparations were obtained as previously described by Le Gac et al. . Briefly, testes were homogenized as described above in homogenization buffer containing 0.3 M sucrose and inhibitors of proteolytic enzymes and were centrifuged at 600 X g for 30 min in order to eliminate undisrupted tissue and cell nuclei. The supernatant was […]

Five micrograms rtGH was radiolabeled with 0.5 mCi 125I-Na (IMS 30; Amersham, Les Ulis, France) by the chlo-ramine T method , with the modification introduced by Martal . The specific activity of 125I-rtGH, calculated by self-displacement with hepatic membrane preparation (5 mg of pellet per tube), was 20 (iCi/mg for studies on testis and 46 […]

Transversal sections from the middle part of the testis were fixed in Bouin’s solution for histological examination. The spermatogenetic stage of each fish was determined according to a classification adapted from Billard and Escaf-fre : Stage I) immature stage with only A spermatogonia; Stage II) beginning of spermatogenesis with spermatogonia A and B; Stage III) […]

Animals One-year-old male rainbow trout (Oncorhynchus mykiss) of the Comec Autumnal strain, reared in natural conditions of temperature (February: 8.5°C; August: 20°C) and photoperiod (48°N) at the INRA experimental fish farm (Sizun, Finistere, France), were used. During the entire experimental period (January-November 1995), fish were kept in circulating fresh-water tanks (capacity 1800 L) and fed […]

In teleost fish, binding sites for homologous GH have been detected in the testis , and Le Gac et al. have, for the first time in a vertebrate, described GH-specific binding with general characteristics of GH-R in rainbow trout testicular membrane preparations. Other studies suggest that these GH-R are functional. Indeed, GH treatments are able […]

Although pituitary gonadotropins are the major regulators of gonad function in vertebrates, an increasing number of reports indicate that growth hormone (GH) could act on ovarian and testicular function (for reviews, see ). Pubertal development that has been delayed in isolated GH deficiency in both humans and animals can be restored by GH treatment . […]

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