Effect of Arachidonic Acid on Oviductal Pressure in the Domestic Hen

In anesthetized hens the influence of intra-aortically injected arachidonic acid (AA) and indo-methacin (IND) on arterial blood pressure and on pressure in all oviductal parts (infundibulum, magnum, isthmus, uterus, and vagina) was studied. AA (250-1000 pg/kg) predominantly resulted in an abrupt hypotension (48.4 ± 3.3 mm Hg). Infundibulum, magnum, isthmus, and uterus responded to AA with a pressure increase (“‘4.20-7.00 mm Hg) and the vagina with a pressure decrease (“.4.54 mm Hg). The observed effects resemble prostaglandin (PG) action. The abrupt fall in blood pressure and the decrease in vaginal pressure could be provoked by PGE-like material. An administration of IND (250-1000 pg/kg), 30 mm before AA, inhibited the AA effect on blood and oviductal pressure, but was without influence on the actions of the prostaglandin F2 or E2. The results suggest the presence of the PG synthetase system in the oviduct of the hen