Effect of benserazide on the levels of pineal 5-hydroxytryptamine, melatonin synthesising enzymes and serum melatonin.
The effect of benserazide, an aromatic L-amino acid decarboxylase inhibitor, has been investigated on pineal 5-hydroxytryptamine content, melatonin synthesising enzyme activities and serum melatonin concn. Increasing doses of benserazide caused increasing reductions in the pineal content of 5-hydroxytryptamine. Dark phase serum melatonin concns were also greatly reduced. The drug abolished the diurnal rhythm of hydroxyindole-O-methyltransferase by increasing the light period activities and decreasing the night levels of this enzyme. Pineal N-acetyltransferase was unaffected. It is concluded that benserazide probably inhibits melatonin synthesis by preventing the formation of the substrate, 5-hydroxytryptamine.
D000121:Acetylserotonin O-Methyltransferase / Q000378:metabolism; D000818:Animals; D065105:Aromatic Amino Acid Decarboxylase Inhibitors; D001191:Arylamine N-Acetyltransferase / Q000378:metabolism; D001545:Benserazide / Q000494:pharmacology*; D002940:Circadian Rhythm / Q000187:drug effects; D006834:Hydrazines / Q000494:pharmacology*; D008027:Light; D008297:Male; D008550:Melatonin / Q000097:blood / Q000378:metabolism*; D010870:Pineal Gland / Q000378:metabolism*; D051381:Rats; D011919:Rats, Inbred Strains; D012701:Serotonin / Q000378:metabolism*
D065105:Aromatic Amino Acid Decarboxylase Inhibitors; D006834:Hydrazines; D012701:Serotonin; D001545:Benserazide; D000121:Acetylserotonin O-Methyltransferase; D001191:Arylamine N-Acetyltransferase; D008550:Melatonin