title: Purification of gonadotropic hormone from the pituitary of the African catfish, Clarias gariepinus (Burchell), and the development of a homologous radioimmunoassay.
abstract: Glycoprotein gonadotropic hormone (GTH) was purified from 2000 pituitaries of male and female African catfish, Clarias gariepinus. The first step was chromatography on concanavalin A-Sepharose followed by filtration on Ultrogel Aca 54, chromatography on DEAE-cellulose, and filtration on Ultrogel Aca 54, respectively. Finally, the purified fractions were analyzed by polyacrylamide gel electrophoresis. The gonadotropic activity in the different fractions was characterized using two tests: the radioimmunoassay for carp gonadotropin-beta subunit was used to quantify the immunoreactive GTH and a cAMP accumulation test was applied to measure the GTH biological activity. The purified glycoprotein GTH was used to raise antibodies and to develop a radioimmunoassay. This resulted in an assay with a variation between assays of approximately 4%, a precision of 4-8%, and an accuracy of 4-8%. GTH levels can be measured over a range of 0.8 to 12.5 ng/ml.
mesh_terms: D000818:Animals; D002397:Catfishes / Q000378:metabolism*; D002845:Chromatography / Q000379:methods; D004591:Electrophoresis, Polyacrylamide Gel; D005260:Female; D007987:Gonadotropin-Releasing Hormone / Q000031:analogs & derivatives / Q000494:pharmacology; D006065:Gonadotropins, Pituitary / Q000302:isolation & purification*; D008297:Male; D009919:Orchiectomy; D010868:Pimozide / Q000494:pharmacology; D010902:Pituitary Gland / Q000032:analysis*; D011863:Radioimmunoassay
chemical_list: D006065:Gonadotropins, Pituitary; D010868:Pimozide; D007987:Gonadotropin-Releasing Hormone; C010661:surfagon