title: Homologous and heterologous adenylate cyclase system desensitization in glial cells.
abstract: In the present research the desensitization of adenylate cyclase system induced by isoproterenol (IPR), a beta-adrenergic agonist, in primary glial cell cultures and the effects of an exposure to 3-isobutyl-1-methylxanthine (IBMX) on the response to a subsequent stimulation with IPR have been investigated. A pretreatment with the phosphodiesterase inhibitor IBMX induced refractoriness to a subsequent IPR challenge suggesting a possible involvement of cAMP in heterologous desensitization. Moreover the present results show that IPR desensitized cells in confluent cultures retained a normal response to cholera toxin, while IBMX treated cells exhibited a reduced response to the toxin. So IPR induces a rather specific desensitization while IBMX induced refractoriness seems to be non specific.
authors.affiliation: Department of Neurology, University of Catania, Italy.
authors.forename: L
authors.initials: L
authors.lastname: Rampello
mesh_terms: D015056:1-Methyl-3-isobutylxanthine / Q000494:pharmacology; D000262:Adenylyl Cyclases / Q000378:metabolism*; D000818:Animals; D002478:Cells, Cultured; D002772:Cholera Toxin / Q000494:pharmacology; D005576:Colforsin / Q000494:pharmacology; D000242:Cyclic AMP / Q000096:biosynthesis*; D004789:Enzyme Activation / Q000187:drug effects; D005260:Female; D007545:Isoproterenol / Q000494:pharmacology; D008297:Male; D009457:Neuroglia / Q000187:drug effects / Q000201:enzymology*; D051381:Rats; D011943:Receptors, Adrenergic, beta / Q000187:drug effects / Q000378:metabolism
chemical_list: D011943:Receptors, Adrenergic, beta; D005576:Colforsin; D002772:Cholera Toxin; D000242:Cyclic AMP; D000262:Adenylyl Cyclases; D007545:Isoproterenol; D015056:1-Methyl-3-isobutylxanthine