Direct and indirect stimulations of cyclic AMP formation in human brain.
1. Adenosine 3':5'-cyclic monophosphate (cyclic AMP) formation, by use of an [3H]-adenine prelabelling assay, was measured in fragments of human cerebral cortex, taken in the course of various neurosurgical procedures. 2. Large accumulations of [3H]-cyclic AMP due to isoprenaline, noradrenaline and adenosine and small effects due to forskolin were observed. Histamine, 5-hydroxytryptamine (5-HT) and the excitatory amino acids glutamate and quisqualate were ineffective. 3. The response to noradrenaline consisted of two components; a direct beta-adrenoceptor response and an enhancement mediated by an alpha-adrenoceptor which appears to be similar to that in rat cerebral cortex. 4. The response to isoprenaline was also potentiated by histamine H1 receptor stimulation but the direct effect of 2-chloroadenosine was not altered by histamine, 5-HT or quisqualate. 5. It is concluded that some, but not all, of the indirect modulations of cyclic AMP formation previously observed in experimental animal brain exist in human cerebral cortex.
Kendall
D A
DA
Department of Physiology, Queens' Medical Centre, Nottingham.
Millns
P J
PJ
Firth
J L
JL
D000225:Adenine / Q000378:metabolism; D000241:Adenosine / Q000494:pharmacology; D002540:Cerebral Cortex / Q000187:drug effects / Q000378:metabolism*; D000242:Cyclic AMP / Q000096:biosynthesis*; D005260:Female; D006801:Humans; D066298:In Vitro Techniques; D007545:Isoproterenol / Q000494:pharmacology; D008297:Male; D009638:Norepinephrine / Q000494:pharmacology; D011224:Prazosin / Q000494:pharmacology; D011738:Pyrilamine / Q000494:pharmacology; D013045:Species Specificity
D000242:Cyclic AMP; D011738:Pyrilamine; D000225:Adenine; D000241:Adenosine; D007545:Isoproterenol; D009638:Norepinephrine; D011224:Prazosin