Effect of antihypertensive drugs on catechol-O-methyltransferase and monoamine oxidase activity in human term placental explants.
The effects of therapeutic concentrations of antihypertensive drugs on catechol-O-methyltransferase (COMT) and monoamine oxidase (MAO) activities in term placental explants were studied. The enzyme activities were measured in tissue fractions using radioenzymatic techniques. At 6 h the incubation COMT activity increased significantly following exposure to verapamil and hydralazine, while exposure to alpha methyldopa caused a significant suppression of the enzyme. At 24 h exposure to hydralazine significantly suppressed the COMT activity. By 6 h the MAO activity was significantly suppressed by verapamil. MgSO4 and propranolol had no effect on the activities of COMT and MAO at 6 and 24 h. These results suggest that COMT and MAO activities in the placenta can be modulated by antihypertensive drugs and, therefore, these drugs might affect local catechol metabolism.
E R
ER
Barnea
H
H
Fakih
G
G
Oelsner
S
S
Walner
A H
AH
DeCherney
F
F
Naftolin
D000959:Antihypertensive Agents / Q000008:administration & dosage / Q000494:pharmacology*; D002394:Catechol O-Methyltransferase / Q000378:metabolism*; D004305:Dose-Response Relationship, Drug; D005260:Female; D006801:Humans; D006830:Hydralazine / Q000008:administration & dosage / Q000494:pharmacology; D066298:In Vitro Techniques; D008278:Magnesium Sulfate / Q000008:administration & dosage / Q000494:pharmacology; D008750:Methyldopa / Q000008:administration & dosage / Q000494:pharmacology; D008995:Monoamine Oxidase / Q000378:metabolism*; D010920:Placenta / Q000187:drug effects / Q000201:enzymology*; D011247:Pregnancy; D011433:Propranolol / Q000008:administration & dosage / Q000494:pharmacology; D013997:Time Factors; D014700:Verapamil / Q000008:administration & dosage / Q000494:pharmacology
D000959:Antihypertensive Agents; D006830:Hydralazine; D008750:Methyldopa; D008278:Magnesium Sulfate; D011433:Propranolol; D014700:Verapamil; D008995:Monoamine Oxidase; D002394:Catechol O-Methyltransferase