The effect of some phenylethanolamine N-methyltransferase inhibitors on the adrenaline content in the domestic fowl diencephalon.
The concentration of adrenaline in the domestic fowl diencephalon was determined by a mass spectrometric or fluorimetric method. The values obtained were 701 and 803 ng/g, respectively. The administration of phenylethanolamine N-methyltransferase (PNMT) (EC 2.1.1.28) inhibitors (SK&F 7698 or SK&F 64139)  to the domestic fowl produced a marked reduction in the diencephalic noradrenaline methylation (from 25% in the controls ot 7--8% in the PNMT-inhibitor-treated animals); the large decrease in adrenaline concentration (to 14--18% of controls) was accompanied by a moderate decrease in noradrenaline concentration (to 63--84% of controls). Reserpine, in contrast, produced a marked reduction of both adrenaline and noradrenaline (to 12 and 17% of controls, respectively) but did not affect the percentage of methylation. It would seem a reasonable assumption that in the domestic fowl diencephalon, adrenaline is formed by N-methylation of noradrenaline and functions there as a transmitter in some specific adrenergic neuronal pathways.
D000818:Animals; D002645:Chickens; D004027:Diencephalon / Q000187:drug effects / Q000378:metabolism*; D004837:Epinephrine / Q000378:metabolism*; D005260:Female; D007546:Isoquinolines / Q000494:pharmacology*; D013058:Mass Spectrometry; D009638:Norepinephrine / Q000378:metabolism; D010625:Phenylethanolamine N-Methyltransferase / Q000037:antagonists & inhibitors*; D011725:Pyridines / Q000494:pharmacology*; D012110:Reserpine / Q000494:pharmacology; D044005:Tetrahydroisoquinolines; D013876:Thiophenes / Q000494:pharmacology
D007546:Isoquinolines; D011725:Pyridines; D044005:Tetrahydroisoquinolines; D013876:Thiophenes; C006214:3-methyl-1,2,3,4-tetrahydro(1)benzothieno(3,2-c)pyridine hydrochloride; D012110:Reserpine; C012153:7,8-dichloro-1,2,3,4-tetrahydroisoquinoline; D010625:Phenylethanolamine N-Methyltransferase; D009638:Norepinephrine; D004837:Epinephrine