Bicarbonate Content of the Blastocyst Fluid and Carbonic Anhydrase in the Pregnant Rabbit Uterus

Abstract

IT has been noted in the course of a chemical investigation of the properties of rabbit blastocysts that the fluid which fills the cavity of the blastocyst at six and seven days after mating turns distinctly alkaline after withdrawal and standing in air for a few moments, whereas at eight days, in similar circumstances, the reaction of the fluid remains practically unaltered, at pH 7.8 ¹. In view of the low buffering capacity of the fluid obtained from six- and seven-day old blastocysts, it was thought likely that bicarbonate may be responsible for the shift in the pH value. Accordingly, manometric determinations were carried out in samples of fluid from blastocysts at six, seven and eight days after mating, collected by means of a technique described elsewhere¹.