Isoprenaline-induced changes in activity of the endogenous inhibitor of cAMP-dependent protein kinases under conditions of beta-adrenoceptor supersensitivity.
Isoprenaline-induced changes in activity of an endogenous, specific inhibitor of cAMP-dependent protein kinases (type I inhibitor) under conditions of experimental supersensitivity of beta-adrenoceptors were investigated in rat hippocampus and brain stem. Both subchronic administration of reserpine (2.5 mg kg-1, i.p., 4 days, once daily) and i.c.v injections of 6-hydroxydopamine (250 micrograms/ventricle, bilaterally, 48 h apart), which are known to increase beta-adrenoceptor sensitivity in the rat brain, markedly enhanced the response of the type I inhibitor activity to isoprenaline. To obtain a significant decrease of type I inhibitor activity in the examined brain structures of these animals, doses of isoprenaline 2-5 times lower than in control groups had to be used. It is suggested that the isoprenaline-induced decrease of type I inhibitor activity might be used as an index of central beta-adrenoceptor reactivity in-vivo.
Zawilska
J
J
Szmigielski
A
A
D000818:Animals; D001933:Brain Stem / Q000378:metabolism; D006624:Hippocampus / Q000378:metabolism; D006892:Hydroxydopamines / Q000494:pharmacology; D007545:Isoproterenol / Q000494:pharmacology*; D008297:Male; D016627:Oxidopamine; D011433:Propranolol / Q000494:pharmacology; D047428:Protein Kinase Inhibitors; D051381:Rats; D011919:Rats, Inbred Strains; D011943:Receptors, Adrenergic, beta / Q000502:physiology*; D012110:Reserpine / Q000494:pharmacology
D006892:Hydroxydopamines; D047428:Protein Kinase Inhibitors; D011943:Receptors, Adrenergic, beta; D012110:Reserpine; D016627:Oxidopamine; D011433:Propranolol; D007545:Isoproterenol