TY - JOUR T1 - CHARACTERIZATION OF THE ADRENERGIC RECEPTORS MEDIATING A RISE IN CYCLIC 3',5'-ADENOSINE MONOPHOSPHATE IN RAT CEREBRAL CORTEX JF - Journal of Pharmacology and Experimental Therapeutics JO - J Pharmacol Exp Ther SP - 371 LP - 378 VL - 185 IS - 2 AU - JOHN P. PERKINS AU - MARILYN M. MOORE Y1 - 1973/05/01 UR - http://jpet.aspetjournals.org/content/185/2/371.abstract N2 - Norepinephrine (NE) causes a 4- to 6-fold rise in the cyclic 3', 5'-adenosine monophosphate content of chopped rat cerebral cortex. The effect is half-maximal at 6 µM and essentially maximal at 30 µM. The effect of 30 µM NE is only partially blocked by maximally effective concentrations (30 µM) of either propranolol or phentolamine. However, the effect is completely blocked when these inhibitors are added together even at lower concentrations (10 µM each). Isoproterenol (ISO) causes only a 2- to 4-fold rise in cyclic 3', 5'-adenosine monophosphate in the same preparation. The effect is half-maximal at 0.4 µM and essentially maximal at 3 µM. The effect of 30 µM ISO is completely blocked by 30 µM propranolol, but phentolamine is without effect. Maximally effective concentrations of NE and ISO together produce an effect similar to that of NE added alone. The results suggest that NE interacts with at least two types of receptors (analogous to alpha and beta) whereas ISO appears to react with a single type (analagous to beta). Analysis of the difference in the time courses of the effects of NE and ISO suggests that a slow component of the NE effect may be indirect. © 1973 by The Williams & Wilkins Co. ER -