ADRENALINE CONCENTRATION IN THE RAT UTERUS AFTER ADRENLINE ADMINISTRATION BY DIFFERENT ROUTES1

Abstract

Experiments were performed to determine why subcutaneous injections of adrenaline did not cause a decrease in glycogen and phosphorylase levels in the rat uterus while intraperitoneal injections did. Intraperitoneal injection of small amounts of adrenaline was followed by a large increase in the uterine level of adrenaline (chemically determined) 10 minutes later, in spayed rats pretreated with estradiol. Subcutaneous injection of similar or larger doses of adrenaline was not followed by an increase in uterine adrenaline levels in 10 minutes. The uterine adrenaline levels, one hour after 100 [mu]g. doses injected subcutaneously, were above the control level but similar to those found one hour after 25 ug. doses, given intraperitoneally. This indicated that a threshold level of adrenaline must be attained rapidly to produce these metabolic effects. Uterine noradrenaline levels were increased one hour after injecting 100 [mu]g. doses of adrenaline subcutaneously.