Urinary Excretion of Adrenalin, Noradrenalin and Vanylmandelic Acid in Rats during Pregnancy and Post-Partum. Effects of Niamide and Reserpine Administration

Abstract

The urinary excretion of catecholamines in rats from the 15th day of pregnancy to post-partum is studied. Adrenalin and vanylmandelic acid (VMA) excretion showed significant changes from the controls during observation period. There was only a slight change in noradrenalin until the 21st day. During and after labor the urinary excretion of adrenalin and noradrenalin reached the maximum level. VMA excretion was higher at 16th day of pregnancy and 24 hours after birth. Niamide administration to control and pregnant rats was followed by rises in catecholamine excretion. Reserpine increased the output of adrenalin and VMA while noradrenalin excretion declined markedly. The combined administration of niamide and reserpine resulted in increased excretion of adrenalin and VMA but noradrenalin declined. The combined or individual administration of niamide and reserpine exerted different effects in control and pregnant rats. The results suggest that increased catecholamine excretion during pregnancy is associated with changes in different hormonal concentrations. The different effects of niamide and reserpine on urinary catecholamine excretion also seem to be attributed to the hormonal state during pregnancy.

Key words

Adrenalin - Vanylmandelic Acid - Catecholamines - Pregnancy - Niamide - Reserpine

1 Research Fellow from Australia, Centre National de la Recherche Scientifique (CNRS), Paris, France. With technical assistance of Miss D. Telliez.