Prostaglandin-induced changes and the influence of cyclo-and lipoxygenase inhibitors on the uterine collagen concentration in late pregnancy in rats.

During late pregnancy, the influence of PGF2 alpha and PGE2 on the collagen concentration in a rat's uterus was analysed. In order to evaluate the influence of endogenous prostaglandins and leukotrienes on connective tissue metabolism, a cyclooxygenase inhibitor (Diclofenac) and a dual cyclo-and 5-lipoxygenase inhibitor (BW755C) were administered prior to the collection of samples. Total collagen and its soluble fraction as well as water content were determined in the uteri in a population of 58 pregnant rats treated with PGF2 alpha (n = 16), PGE2 (n = 11), Diclofenac (n = 11), BW755C (n = 7) and controls (n = 13). The most evident changes in tissue hydration and collagen concentration were observed in the PGF2 alpha and Diclofenac treated groups. The results clearly show the affinity of PGF2 alpha to the uterus and the role of endogenous PGs in the maintenance of pregnancy by influencing connective tissue metabolism.