[Influence of arachidonic acid metabolic inhibitors upon uterine contractions]

The stimulating action of uterine contractions of cyclooxygenase products and 5-lipoxygenase products in an arachidonic acid cascade and the role of the inhibitors of both pathways have recently been the subject of much attention. We studied the influences of these drugs using the myometriums of pregnant rats. The inhibitory effects on pregnant uterine contractions (in vitro) were in the order beta 2-stimulants (procaterol, pirbuterol) greater than AA-861 greater than flurbiprofen greater than indomethacin greater than BW-755C. The inhibitory potency was reinforced by concurrent administration of AA-861 and flurbiprofen. Stimulation of the uterine contractions by Leukotriene (LT) was LTD4 greater than LTC4, and also the inhibition of the LT strain was AA-861 greater than flurbiprofen. The stimulation of PGE1 analog (ONO-802) revealed the reaction of LT + AA-861 (-) and LT + flurbiprofen (+/-). As to the changes in c-AMP and c-GMP in the bath medium before and after the administration of each drug, the change in the administration of the LT strain was slight, and an increase in c-AMP and a decrease of c-GMP were noted following the administration of contraction inhibitory substances. Its variation ratios were noted, in the order: increase in c-AMP of AA-861 + flurbiprofen greater than pirbuterol AA-861 greater than BW-755C, and decrease in c-GMP of pirbuterol greater than AA-861 + flurbiprofen greater than A-861 greater than BW-755C.