Does maximal serotonin N-acetyltransferase activity necessarily reflect maximal melatonin production in the rat pineal gland?
p-Chlorophenylalanine (PCPA) treatment reduced pineal 5-hydroxytryptamine (5-HT) levels by 68.9% of non-PCPA treated levels in intact rat pineal glands and by 95.9% of non-PCPA treated levels in adrenergically denervated rat pineal glands. Although isoproterenol stimulation resulted in increased activity of serotonin N-acetyltransferase (NAT) activity in all experimental groups, pineal melatonin production was maximal only in non-PCPA treated rats, suggesting that 5-HT concentrations may exert considerable influence on the level of melatonin production in the rat pineal gland, independent of the level of NAT activity.
D000123:Acetyltransferases / Q000378:metabolism*; D000818:Animals; D001191:Arylamine N-Acetyltransferase / Q000378:metabolism*; D010134:Fenclonine / Q000494:pharmacology; D005728:Ganglia, Sympathetic / Q000502:physiology; D007545:Isoproterenol / Q000494:pharmacology; D008297:Male; D008550:Melatonin / Q000096:biosynthesis*; D010870:Pineal Gland / Q000187:drug effects / Q000201:enzymology*; D051381:Rats; D011919:Rats, Inbred Strains; D012701:Serotonin / Q000378:metabolism
D012701:Serotonin; D000123:Acetyltransferases; D001191:Arylamine N-Acetyltransferase; D008550:Melatonin; D007545:Isoproterenol; D010134:Fenclonine