mu-Opioid agonist-stimulated [35S]GTPgammaS binding in guinea pig hypothalamus: effects of estrogen.
mu-Opioid receptors play a critical role in the regulation of the female reproductive cycle, and estrogen modulates the coupling of mu-opioid receptors to a potassium channel in the basal hypothalamus (BH) of the female guinea pig. Therefore, we ascertained the distribution of mu-opioid receptors in the BH with autoradiography using the mu-opioid selective agonist [3H]DAMGO. In addition, we investigated the effects of estrogen on DAMGO- or the GABAB receptor agonist baclofen-stimulated [35S]GTPgammaS binding in the BH. Based on the high density of mu-opioid receptors, but the lack of effects of estrogen on [35S]GTPgammaS binding, we conclude that mu-opioid receptor interaction with its G-protein is not the target of estrogen's actions.
Cunningham
M J
MJ
Department of Physiology and Pharmacology, L334, Oregon Health Sciences University, Portland, OR 97201, USA.
Fang
Y
Y
Selley
D E
DE
Kelly
M J
MJ
D000818:Animals; D020875:Enkephalin, Ala(2)-MePhe(4)-Gly(5)-; D004745:Enkephalins / Q000378:metabolism / Q000494:pharmacology*; D004967:Estrogens / Q000494:pharmacology*; D005260:Female; D016244:Guanosine 5'-O-(3-Thiotriphosphate) / Q000378:metabolism*; D006168:Guinea Pigs; D007031:Hypothalamus / Q000187:drug effects* / Q000378:metabolism; D009490:Neurosecretory Systems / Q000187:drug effects; D015221:Potassium Channels / Q000187:drug effects; D011869:Radioligand Assay; D017450:Receptors, Opioid, mu / Q000819:agonists*; D013268:Stimulation, Chemical; D013462:Sulfur Radioisotopes
D004745:Enkephalins; D004967:Estrogens; D015221:Potassium Channels; D017450:Receptors, Opioid, mu; D013462:Sulfur Radioisotopes; D020875:Enkephalin, Ala(2)-MePhe(4)-Gly(5)-; D016244:Guanosine 5'-O-(3-Thiotriphosphate)