Endocrine Control of Free Amino Acids Content in Uterine Fluid in Pregnant Rabbits

Abstract

Free amino acid content was measured in the uterine fluid and blood serum in the following groups of rabbits 168 h post copulation: intact; intact progesterone-treated; ovariectomized progesterone-treated; ovariectomized progesterone-oestradiol-treated; and ovariectomized without hormonal treatment. At implantation, concentration of the majority of amino acid in uterine fluid exceeded greatly that of blood serum; the difference in concentration being maximal for glycine, taurine, alanine, glutamic acid, aspartic acid, serine and threonine. Glutamine-asparagine and arginine were found in comparable quantities or were even higher in blood serum. Glycine, alanine, taurine, glutamic acid, serine and glutamine-asparagine were found in highest concentration in the uterine fluid. The level of ammonia in uterine fluid was also relatively high. Exogenous progesterone and oestradiol caused significant changes in the concentration of some amino acid. The concentration of glycine, taurine, alanine, serine, glutamic acid, aspartic acid, threonine, \m=1/2\ cystine and histidine seems to be especially hormonally dependent. The results are discussed in relation to hormonal activity of corpora lutea during early pregnancy, physiological significance of free amino acids in uterine fluid and nourishment of an early embryo.

Free Amino Acid Content of Ewe Uterine Fluid Under Various Hormonal Treatments During Early Pregnancy

“…It also provides a nutritive medium reflecting blastocyst needs. In rabbit, the maximum concentration of free amino acids in the uterine lumen coincides with the presence of the unattached blastocyst (J ASZCZAK et al, 1972 ), which imperatively needs an amino nitrogen source for further development (B RINS TE R , ig 7 o). Our 1971), the total concentration of free amino acids in the ewe is higher using absorption on paper strips than using a cannulation technic (WALES, 1973 ;M!rr!zo, 1973 ).…”