Dopamine and Epinephrine Infusion Reduce Clearance Rate of Rat Prolactin in the Female Rat 1

Abstract

Summary

The iv infusion of dopamine (250 or 500 ng/min) or epinephrine (500 or 1000 ng/min) into adult female cycling rats in each instance caused a threefold elevation in the equilibrium concentration of prolactin (PRL) in the plasma resulting from the continuous infusion of 200 ng rat PRL/min. A single iv injection of 1 μg dopamine had no effect upon equilibrium PRL levels. The metabolic clearance rate of PRL was significantly reduced from 1.35 to 0.44 ml/min as a result of infusing either 250 or 500 ng dopamine/min, and from 1.14 to 0.37 and from 1.56 to 0.65 ml/min from infusing 500 and 1000 ng/min, respectively, of epinephrine.

I am grateful to the National Institute of Arthritis, Metabolism and Digestive Diseases (NIAMDD) Rat Pituitary Hormone Distribution Program for the gift of rat PRL, and to Tanya McGee for expert technical assistance.