ABSTRACT
A detailed study has been made of the progesterone content of uterine flushings taken from rabbits of different endocrine states. A high content of progesterone was recovered from the uterine lumen of pregnant and pseudopregnant rabbits. The amount of progesterone recovered in the flushings was not simply dependent on the concentration in the plasma, because plasma progesterone concentrations rose before detection of progesterone in the flushings and remained high after uterine progesterone content had fallen. Progesterone did not appear in the uterine fluid unless uterine protein was present. This was particularly evident in rabbits treated with progesterone in which, despite abnormally high plasma concentrations, little progesterone was found in uterine fluid until the protein content increased. After treatment of rabbits with oestrogen at the time of ovulation, uterine progesterone was present in higher amounts concomitant with an elevation of protein content although the peak values of progesterone and protein were delayed by 2--3 days. Plasma progesterone concentrations of about 5 ng/ml were necessary before progesterone appeared in the uterine lumen.
Subject(s)
Progesterone/analysis , Uterus/analysis , Animals , Chorionic Gonadotropin/pharmacology , Estradiol/analogs & derivatives , Estradiol/pharmacology , Female , Pregnancy , Progesterone/blood , Progesterone/pharmacology , Proteins/metabolism , Pseudopregnancy , Rabbits , Uterus/drug effects , Uterus/metabolismABSTRACT
Fertilized and unfertilized mouse eggs were examined by scanning and transmission electron microscopy for evidence of mosaicism in the organization and concanavalin A-binding properties of their surface membranes. No obvious quantitative mosaicism in concanavalin A binding was noted. The egg membrane was microvillous over most of its surface, but was smooth in the region overlying the 2nd metaphase spindle of the unfertilized egg and on the polar body of the fertilized egg.
