Activity of hyaluronidase in placental tissues from cows with and without retained fetal membranes.

Hyaluronidase, a proteoglycan-degrading enzyme, may have an influence on collagenolysis in bovine placenta and take part in the separation processes of the placenta in cows. There was, however, no evidence concerning the activity of this enzyme in those tissues. The experiment was performed on cows divided into two groups as follows: A, placenta not retained (n = 16); and B, placenta retained (n = 9). The activity of the enzyme was measured using a spectrophotometric method and zymography. The results showed statistically significant higher activity of hyaluronidase in the maternal and fetal parts of the placenta in cows with a retention of fetal membranes. Further experiments require substrate specificity studies and the presence of regulatory factors of this enzyme in bovine placental tissues.

Activity of placental glutathione peroxidase and superoxide dismutase in cows with and without retained fetal membranes.

Changes in the levels of the activity of two enzymes that neutralize free radicals-glutathione peroxidase [(EC.1.11.1.9), GSH-Px] and superoxide dismutase--[(EC.1.15.1.1), SOD]--in cows with fetal membranes retention (RFM) were studied. The activities were measured in maternal and fetal placental tissues after spontaneous parturition without (group A) and with (group B) retained placenta. GSH-Px activities were higher in group B than in group A (P < 0.05). The activity of this enzyme was lower in the maternal than in the fetal part of the placenta in both groups. The activity of SOD was significantly (P < 0.05) lower in maternal part, and higher in fetal part, of placenta in group B compared with group A. Experiments on defence mechanisms against free radicals in periparturient cows in connection with more frequent sampling, prostaglandins levels, oxidative stress, nutrition and retained placenta are required to further elucidate the role of these enzymes.