A system for continuous, volumetric collection of oviduct secretions was applied to New Zealand White rabbits. After 3 or more days, animals were mated. The secretion rate decreased on the 2nd and 3rd days of pregnancy. It leveled off at about 50% of the estrous rate and then remained steady during the succeeding 7 days. A similar decrease in rate was observed in pseudopregnancy. No decrease was observed in animals that rejected the male or in one that mated but failed to become either pregnant or pseudopregnant. The sodium concentration was significantly lower in the first 3 days of pregnancy (mean 142.6 mEq/l.) than in estrus (mean 144.5 mEq/l.). A significant change in potassium (mean 6.2 mEq/l.) and chloride (mean 118.7 mEq/l.) levels was not demonstrated. The reducing sugar content (mean 6 mg %) displayed no variation in relation to ovulation. Glycine, glutamic acid, alanine, valine and leucine were consistently present. The lactic acid concentration varied widely among the animals (range 4.4–51.0 mg%). In the group, it was increased significantly in early pregnancy.
Trophoblast-derived Lactic Acid Orchestrates Decidual Macrophage Differentiation via SRC/LDHA Signaling in Early Pregnancy
