Changes of enzyme activities in ovine fetal fluids and maternal blood serum with gestational age

Abstract

Our objectives were threefold: (1) to assess the activities of tissue enzymes, aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatase (ALP), lactate dehydrogenase (LDH), and creatine kinase (CK) in the fetal fluids (amniotic and allantoic) collected from the gravid sheep uteri obtained from the abattoir and also in the maternal blood serum at various stages of pregnancy, (2) to compare the enzyme activities of fetal fluids relative to the maternal serum, and (3) to compare the enzyme activities in serum of pregnant ewes to nonpregnant ones. The stages of gestation, viz., stage I (30–60 days), stage II (61–90 days), and stage III (91–120 days) were identified based on the crown anus length of the fetus. As the gestational ages increased, AST significantly (p < 0.01) increased in the amniotic fluid and maternal blood serum but decreased in allantoic fluid; ALT had no changes in fetal fluids and the maternal blood serum; ALP decreased significantly (p < 0.01) in allantoic fluid but had no changes in the amniotic fluid and maternal serum; LDH increased significantly (p < 0.01) in amniotic and allantoic fluids but decreased in maternal serum; CK decreased significantly (p < 0.01) in fetal fluids and maternal serum. The enzyme activities were significantly higher in maternal sera than fetal fluids but were successively less in allantoic and amniotic fluids (p < 0.01). The activity of enzymes in maternal sera of pregnant and nonpregnant ewes were nearly the same. Except for LDH and CK, the greatest activities were found in the maternal serum in stage I and for AST in stage III of pregnancy (p < 0.01). These findings may have appreciable diagnostic significance in prenatal detection of disease status in both the dam and the fetus.