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A Comparison of the Binding of [ 3 H]Proprionyl‐Neuropeptide Y to Rat and Human Frontal Cortical Membranes
Author(s) -
Widdowson Peter S.,
Halaris Angelos E.
Publication year - 1990
Publication title -
journal of neurochemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.75
H-Index - 229
eISSN - 1471-4159
pISSN - 0022-3042
DOI - 10.1111/j.1471-4159.1990.tb04584.x
Subject(s) - neuropeptide y receptor , peptide yy , gtp' , receptor , pancreatic polypeptide , endocrinology , medicine , binding site , population , chemistry , membrane , g protein , biology , neuropeptide , biochemistry , hormone , enzyme , glucagon , environmental health
The binding characteristics of [ 3 H]proprionyl‐neuropeptide Y ([ 3 H]proprionyl‐NPY) were studied in frontal cortical membranes prepared from rat and human postmortem tissue. The specific binding of NPY decreased as the magnesium concentration increased from 1.05 to 10 m M . The binding was also influenced by the concentration of GTP in the buffer medium, with a resulting 45% decrease in NPY binding in the presence of 10 ‐ ‐ 6 M GTP. Using equilibrium binding studies, [ 3 H]proprionyl‐NPY was found to bind in both tissues with high affinity to a single class of receptors with a similar K D (0.035 n M ). However, kinetic experiments in both tissues provided evidence for two components of [ 3 H]proprionyl‐NPY binding which may be related to receptor states. Competition binding experiments showed that peptide YY (PYY) was equal to NPY in its ability to displace [ 3 H]proprionyI‐NPY, whereas rat and human pancreatic polypeptide were without effect up to a concentration of 10 ‐ ‐ 6 M . This suggests that, whereas PYY and NPY may compete for the same receptor(s), the pancreatic polypeptides probably act on a separate population of receptors.