Beta-adrenoceptor and post-receptor components show different rates of desensitization to desipramine.
Both 3-day and 15-day desipramine treatments (10 mg/kg, once daily) significantly reduced beta 1- but not beta 2-adrenoceptor and isoproterenol-stimulated adenylyl cyclase activities in rat cortical, hippocampal and amygdaloid membrane preparations. In contrast, 15-day but not 3-day desipramine treatment resulted in a significant reduction in NaF-, GppNHp- and forskolin-stimulated adenylyl cyclase activity. The results suggest that post-beta-adrenoceptor component desensitization occurs more slowly than receptor downregulation in response to desipramine.
Tiong
A H
AH
Department of Pharmacology, University of Saskatchewan, Saskatoon, Canada.
Richardson
J S
JS
D000262:Adenylyl Cyclases / Q000378:metabolism; D000818:Animals; D001921:Brain / Q000201:enzymology; D001923:Brain Chemistry / Q000187:drug effects; D002384:Catalysis; D003891:Desipramine / Q000494:pharmacology*; D015536:Down-Regulation / Q000187:drug effects; D066298:In Vitro Techniques; D007457:Iodine Radioisotopes; D007545:Isoproterenol / Q000494:pharmacology; D008297:Male; D051381:Rats; D011919:Rats, Inbred Strains; D011943:Receptors, Adrenergic, beta / Q000187:drug effects* / Q000378:metabolism
D007457:Iodine Radioisotopes; D011943:Receptors, Adrenergic, beta; D000262:Adenylyl Cyclases; D007545:Isoproterenol; D003891:Desipramine