Effects of Lyophilization and Freezing on the Analysis of Mouse Uterine Lumenal Fluids and Qualitative Aspects of Secretions from Breeder and Nonbreeder Mice

Abstract

Abstract

Uterine flushings were obtained from 160 ICR albino breeder and nonbreeder mice classified as either in estrus or in the nonestrus stage of cycle to evaluate proteins by electrophoresis. In the initial experiment, uterine flushings were frozen or lyophilized before disc-gel electrophoresis. Lyophilization resulted in a significant loss of protein constituent from the samples. In a second experiment using only frozen samples, fewer protein bands were found following disc—gel electrophoresis in estrous flushing from mice that had previously littered than in estrous flushing of nonbreeder mice which had been previously exposed to males and had not conceived. There appears to be qualitative differences in y protein peaks, with nonbreeder mice having fewer peaks during estrus and an excess of an ã peak protein during the nonestrual phase of the cycle. The excess ã protein during nonestrus may be indicative of a hostile uterine environment and be related to lowered reproductive efficiency.