Prostaglandins and the contractile function of the human oviductal ampulla

Millimeter-wide muscle strips were prepared from the circular and longitudinal musculature of the oviductal ampulla of fertile women. These specimens were mounted in organ baths for isometric recording of contractile activity. The two types of strips exhibited similar rhythmic spontaneous activity which was found to be present in all phases of the menstrual cycle. Prostaglandin E2 (PGE2) caused an inhibition of contractile activity in both the circular and longitudinal layers, whereas PGF2 alpha induced a marked excitatory response in the specimens. Administration of prostacyclin (PGI2) also elicited an excitatory effect although much less pronounced that that of PGF2 alpha. Pretreatment with ETA, a blocker of endogenous prostaglandin synthesis, abolished the spontaneous contractile activity in a concentration-dependent manner. It is concluded that the ampullary portion of the human oviduct possesses pharmacological properties which differ in certain important respects from those of the isthmus. A shift in the tissue levels of endogenous prostaglandin levels may occur in sequence with ovulation and the pattern of the prostaglandins synthesized seems to be appropriate for the contractile function of the various tubal segments during ovum transport in women.