Uptake of [3H]-arachidonic acid by human endometrium. Differences between normal and menorrhagic tissue.

Human proliferative and secretory endometrium from normal women and from menorrhagic patients was maintained in culture for up to 24 h in the presence of [3H]-arachidonic acid (3H-AA). This prostaglandin (PG) precursor was incorporated into endometrial neutral lipids and phospholipids in a time-dependent manner. Uptake of 3H-AA into phospholipids was significantly higher in normal secretory endometrium than in normal proliferative endometrium. However, this increased uptake of 3H-AA into phospholipids between the 2 phases of the cycle did not occur in menorrhagic endometrium. In contrast, uptake of 3H-AA into neutral lipids (especially triglyceride) was approximately 2-fold higher in menorrhagic endometrium compared to normal endometrium at both stages of the cycle, particularly during the proliferative phase. Abnormalities apparently exist in menorrhagic endometrium in the uptake processes which control arachidonic acid (AA) turnover. These abnormalities may be responsible, in part for abnormal PG production by menorrhagic endometrium.