Phosphorylase Activity in the Pseudopregnant Rat Uterus

Abstract

Phosphorylase activity was determined in the rat uterus during pseudo-pregnancy in the deciduoma and myometrium of traumatized horns and in contralateral untraumatized horns. Phosphorylase a activity decreased during the life of the deciduoma while that in the myometrium remained relatively constant. The phosphorylase activity in the entire traumatized uterine horn was higher than in the untraumatized contralateral control horn. The increase in enzyme activity on Day 4 of pseudopregnancy above the low level observed on the first day post estrus coincides with the reported "estrogen surge." Distention of the uteri of ovariectomized rats, induced by inserting glass rods, increased phosphorylase activity to a level higher than that observed in the uterine horns containing the deciduoma. Factors affecting phosphorylase activity in the pseudopregnant uterus are discussed.