Monoamine Oxidase, Catechol-O-methyltransferase and Phenylethanolamine-N-methyltransferase Activity in Para-aortic Tissue of the Human Fetus

Abstract

Paraganglia of mid-term human fetuses exhibited high monoamine oxidase (MAO) (> in fetal heart and liver), somewhat lower phenylethanolamine-N-methyltransferase (PNMT) (< in fetal adrenals) and no catechol-O-methyltransferase (COMT) activity. The noradrenaline content ranged 115–184 and adrenaline content 2–5 μg/g tissue. The findings indicate that catecholamine inactivation in this organ is performed by MAO and that the adrenaline found is formed locally.

Key Words:

• Catecholamines
• catechol-O-methyltransferase
• chromaffin system
• fetus
• methylation
• monoamine oxidase
• phenylethanolamine-N-methyltransferase