DETECTION OF ACYL-COA SYNTHETASE, ACYL-COA-LYSOPHOSPHOLIPID ACYLTRANSFERASE AND PHOSPHOLIPASE A(2) ACTIVITIES IN NONPREGNANT AND PREGNANT GUINEA-PIG UTERINE TISSUES

Acyl-CoA synthetase (ACS), acyl-CoA:lysophospholipid acyltransferase ( ACLAT) and phospholipase (PL) A(2) activities were detected in guinea- pig endometrium on days 7 and 15 of the cycle, and on days 15, 29 and 36 of pregnancy. Ovariectomy of non-pregnant animals resulted in an in crease in the apparent activities of these three enzymes which was rev ersed by treatment with oestradiol and/or progesterone. ACS, ACLAT and PLA(2) activities were detected in day 15 conceptuses, and in the pla centa, sub-placenta, chorion and amnion on days 29 and 36 of pregnancy . Apparent activities of the enzymes were generally higher in the feta l membranes than in the placental tissue. This study has established t hat the enzymes involved in turnover of arachidonic acid in phospholip ids are present in tissues in the non-pregnant and pregnant guinea-pig uterus. The higher apparent activities of enzymes (ACS and ACLAT) inv olved in arachidonic acid uptake compared to the enzyme (PLA(2)) invol ved in arachidonic acid release is in agreement with there being very low concentrations of free arachidonic acid in tissues.