Author:

Keywords:

trout oncorhynchus-mykiss, carassius-auratus, rainbow-trout, common carp, in-vitro, sensitive radioimmunoassay, cyprinus-carpio, coho salmon, goldfish, pituitary, Science & Technology, Life Sciences & Biomedicine, Endocrinology & Metabolism, Zoology, TROUT ONCORHYNCHUS-MYKISS, CARASSIUS-AURATUS, RAINBOW-TROUT, COMMON CARP, IN-VITRO, SENSITIVE RADIOIMMUNOASSAY, CYPRINUS-CARPIO, COHO SALMON, GOLDFISH, PITUITARY, Animals, Apomorphine, Catfishes, Cells, Cultured, Cross Reactions, Dopamine Agonists, Dose-Response Relationship, Drug, Female, Gonadotropin-Releasing Hormone, Growth Hormone, Hormone Antagonists, Immune Sera, Immunohistochemistry, Injections, Intraperitoneal, Iodine Radioisotopes, Male, Pituitary Gland, Rabbits, Radioimmunoassay, Reproducibility of Results, Sensitivity and Specificity, Sermorelin, Somatostatin, 0606 Physiology, 0608 Zoology, 0707 Veterinary Sciences, 3109 Zoology, 3202 Clinical sciences

Abstract:

A highly sensitive radioimmunoassay has been developed for measuring plasma growth hormone (GH) concentrations in the African catfish (Clarias gariepinus). The lower detection limit of the assay was 0.1 ng/ml and the standard curve had an ED(50) value of 0.5 ng/ml. The validity of the assay was established and the effects of several neurotransmitters on the release of GK were examined. In vitro experiments, using a static culture system for dispersed pituitary cells, demonstrated that the GH release in African catfish was affected by growth hormone-releasing hormone and somatostatin. Single intraperitoneal injections with a dopamine agonist, apomorphine, produced significant and dose-dependent increases in plasma GH levels. Unlike carp, goldfish, and tilapia, a super-active analogue of salmon gonadotrophin-releasing hormone did not alter plasma GH levels in African catfish. (C) 1996 Academic Press, Inc.