Characterization of gonadotropin-releasing hormone binding sites in the pituitary of the three-spined stickleback, Gasterosteus aculeatus

• Published in: General and comparative endocrinology Vol. 76; no. 1; pp. 41 - 45
• Main Authors: Andersson, Eva, Borg, Bertil, Leeuw, Renato De
• Format: Journal Article
• Language: English
• Published: San Diego, CA Elsevier Inc 01.10.1989; Elsevier
• Subjects: Animals; Binding Sites; Biological and medical sciences; Female; Fishes - metabolism; Fundamental and applied biological sciences. Psychology; Hypothalamus. Hypophysis. Epiphysis. Urophysis; Male; Morphology. Functional localizations; Pituitary Gland - cytology; Pituitary Gland - metabolism; Pituitary Gland - ultrastructure; Pituitary Hormone-Releasing Hormones - metabolism; Receptors, LHRH - metabolism; Time Factors; Vertebrates: endocrinology; Brackish water environment; Saturation curve; Endocrine gland; Peptide hormone; Gonadotropin RH; Hypothalamic hormone; Freshwater environment; Vertebrata; Analog; Pisces; Pituitary gland; Scatchard plot; Hormone releasing factor; Column chromatography; Gasterosteus aculeatus; Hormonal receptor
• ISSN: 0016-6480; 1095-6840
• DOI: 10.1016/0016-6480(89)90030-0

Binding sites for gonadotropin-releasing hormone (GnRH) in stickleback pituitary homogenates were characterized using an iodinated, superactive analog of salmon GnRH (sGnRH), d-Arg 6-Pro 9-sGnRH-NEt (sGnRHa). Binding of 125I-sGnRHa reached equilibrium after 60 min incubation at 4° and was a function of tissue concentration. The specificity of 125I-sGnRHa binding was demonstrated by displacement with sGnRHa, sGnRH, and Buserelin [ d-Ser(t-Bu) 6-Pro 9-GnRH-NEt]. Both Scatchard analyses of saturation data and displacement curves revealed a single class of high-affinity binding sites ( K a = 0.71 ± 0.03 × 10 9 M −1, B max = 1087 ± 165 fmol/mg protein).