Determination of guanine nucleotide sensitivity of [125-I]-neuropeptide Y binding in the rat pituitary gland by quantitative autoradiography.
[125I]-neuropeptide Y receptors were characterized in the rat pituitary gland using quantitative autoradiography. Scatchard analysis of saturation isotherms showed high affinity (Kd 8.5 x 10(-11) M) and single class of binding sites (Bmax 0.22 pmol/mg of protein) in the posterior lobe of the pituitary gland, with no specific binding in the intermediate or anterior lobe. Increasing concentrations of guanine nucleotide analogues and peptide YY inhibited neuropeptide Y binding. In addition, neuropeptide Y binding was pertussis-toxin-sensitive. These results add additional information about a possible neuronal (through neuropeptide Y) and hormonal (through peptide YY) regulation of posterior pituitary function, which is most probably GTP-dependent.
Torda
T
T
Section on Pharmacology, National Institute of Mental Health, Bethesda, Md.
Saavedra
J M
JM
D000818:Animals; D001345:Autoradiography; D001667:Binding, Competitive; D006150:Guanine Nucleotides / Q000494:pharmacology*; D016244:Guanosine 5'-O-(3-Thiotriphosphate) / Q000494:pharmacology; D006165:Guanylyl Imidodiphosphate / Q000494:pharmacology; D008297:Male; D009478:Neuropeptide Y / Q000378:metabolism*; D019894:Peptide YY; D010455:Peptides / Q000378:metabolism; D037342:Pertussis Toxin; D010902:Pituitary Gland / Q000187:drug effects / Q000378:metabolism*; D010903:Pituitary Gland, Anterior / Q000378:metabolism; D010904:Pituitary Gland, Posterior / Q000378:metabolism; D051381:Rats; D011919:Rats, Inbred Strains; D017476:Receptors, Neuropeptide Y; D017981:Receptors, Neurotransmitter / Q000378:metabolism*; D010566:Virulence Factors, Bordetella / Q000494:pharmacology
D006150:Guanine Nucleotides; D009478:Neuropeptide Y; D010455:Peptides; D017476:Receptors, Neuropeptide Y; D017981:Receptors, Neurotransmitter; D010566:Virulence Factors, Bordetella; D019894:Peptide YY; D006165:Guanylyl Imidodiphosphate; D016244:Guanosine 5'-O-(3-Thiotriphosphate); D037342:Pertussis Toxin