Pineal serotonin N-acetyltransferase activity: abrupt decrease in adenosine 3',5'-monophosphate may be signal for "turnoff".
Dispersed pinealocytes have been used to study the role of adenosine 3',5'-monophosphate (cyclic AMP) in the "turnoff" of N-acetyltransferace activity. Activity was first stimulated 100-fold by treating cells with 1-norepinephrine. 1-Propranolol acted stereospecifically to rapidly reverse this, resulting in a 70 percent loss of enzyme activity within 15 minutes. An even more rapid 1-propranolol-induced decreased in cyclic AMP also occurred. This together with the observation that the inhibitory effect of 1-propranolol on N-acetyltransferase was blocked by dibutyryl cyclic AMP and phosphodiesterase inhibitors indicate that an abrupt decrease in cyclic AMP may be the signal for the rapid decrease in pineal N-acetyltransferase activity.
D000123:Acetyltransferases / Q000037:antagonists & inhibitors / Q000378:metabolism*; D000818:Animals; D003994:Bucladesine / Q000494:pharmacology; D000242:Cyclic AMP / Q000378:metabolism*; D066298:In Vitro Techniques; D010726:Phosphodiesterase Inhibitors / Q000494:pharmacology; D010870:Pineal Gland / Q000378:metabolism*; D011433:Propranolol / Q000037:antagonists & inhibitors / Q000494:pharmacology; D051381:Rats; D012701:Serotonin
D010726:Phosphodiesterase Inhibitors; D012701:Serotonin; D003994:Bucladesine; D011433:Propranolol; D000242:Cyclic AMP; D000123:Acetyltransferases