Carbachol-induced phosphoinositide metabolism in slices of rat substantia nigra pars reticulata.
Carbachol produced an approximately 2-fold stimulation, with respect to basal, of [3H]inositol monophosphate ([3H]IP1) accumulation in microdissected slices of rat substantia nigra pars reticulata (SNr), measured as a percentage of [3H]inositol incorporation. The response to carbachol was inhibited by 75 +/- 7% by 1 microM pirenzepine, consistent with a muscarinic M1 receptor-mediated response. Carbachol-induced [3H]IP1 accumulation was not reduced by pretreatment of the SNr slices with NMDA, in contrast to the 85% inhibition observed in striatal slices. The results suggest that measurement of carbachol-induced phosphoinositide hydrolysis may be a feasible approach for studying muscarinic M1 receptor function in slices of SNr.
Arias-Montaño
J A
JA
Department of Pharmacology, University of Cambridge, UK.
Aceves
J
J
Young
J M
JM
D000818:Animals; D002217:Carbachol / Q000037:antagonists & inhibitors / Q000494:pharmacology*; D006868:Hydrolysis; D066298:In Vitro Techniques; D008297:Male; D008846:Micromanipulation; D016202:N-Methylaspartate / Q000494:pharmacology; D010716:Phosphatidylinositols / Q000378:metabolism*; D010890:Pirenzepine / Q000494:pharmacology; D051381:Rats; D017208:Rats, Wistar; D011976:Receptors, Muscarinic / Q000187:drug effects; D013378:Substantia Nigra / Q000187:drug effects* / Q000378:metabolism
D010716:Phosphatidylinositols; D011976:Receptors, Muscarinic; D010890:Pirenzepine; D016202:N-Methylaspartate; D002217:Carbachol