RT Journal Article
SR Electronic
T1 Regulation of the Adenosine Cyclic 3',5'-Monophosphate Content of Rat Cerebral Cortex: Ontogenetic Development of the Responsiveness to Catecholamines and Adenosine
JF Molecular Pharmacology
JO Mol Pharmacol
FD American Society for Pharmacology and Experimental Therapeutics
SP 774
OP 782
VO 9
IS 6
A1 JOHN P. PERKINS
A1 MARILYN M. MOORE
YR 1973
UL http://molpharm.aspetjournals.org/content/9/6/774.abstract
AB The ontogenetic development of the regulation of adenylate cyclase by adenosine and catecholamines was studied in slices of cerebral cortex of rats from birth to 18 days of age. Incubation of slices in the presence of 100 , µM adenosine did not lead to an increased accumulation of cyclic AMP until the fifth day after birth. The magnitude of the response to adenosine then increased gradually to maximal levels by day 15. In contrast, responsiveness to catecholamines did not develop until 11-12 days after birth, whereupon the system attained maximal responsiveness within 2-3 days. Prior to the development of sensitivity to catecholamines alone, combination of norepinephrine with adenosine resulted in potentiation of the ability of adenosine to increase cyclic AMP levels in the slices. The catalytic activity of adenylate cyclase, measured in cell-free homogenates of rat cortex, was substantial at birth and increased 3-fold by day 20. The results suggest two alternative interpretations: either the adenylate cyclase of rat cerebral cortex undergoes a progressive development of responsiveness to catecholamines or there is a distinct class of adrenergic receptors involved in the potentiative effects of norepinephrine and another class which mediates the effects of norepinephrine alone.