Characterization of gonadotropin-releasing hormone binding sites in the pituitary of the three-spined stickleback, Gasterosteus aculeatus.
Binding sites for gonadotropin-releasing hormone (GnRH) in stickleback pituitary homogenates were characterized using an iodinated, superactive analog of salmon GnRH (sGnRH), D-Arg6-Pro9-sGnRH-NEt (sGnRHa). Binding of 125I-sGnRHa reached equilibrium after 60 min incubation at 4 degrees 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-Pro9-GnRH-NEt]. Both Scatchard analyses of saturation data and displacement curves revealed a single class of high-affinity binding sites (Ka = 0.71 +/- 0.03 X 10(9) M-1, Bmax = 1087 +/- 165 fmol/mg protein).
Andersson
E
E
Department of Zoology, University of Stockholm, Sweden.
Borg
B
B
de Leeuw
R
R
D000818:Animals; D001665:Binding Sites; D005260:Female; D005399:Fishes / Q000378:metabolism*; D008297:Male; D010902:Pituitary Gland / Q000166:cytology / Q000378:metabolism* / Q000648:ultrastructure; D010906:Pituitary Hormone-Releasing Hormones / Q000378:metabolism*; D011966:Receptors, LHRH / Q000378:metabolism*; D013997:Time Factors
D010906:Pituitary Hormone-Releasing Hormones; D011966:Receptors, LHRH