CANINE GASTRO-INTESTINAL MOTILITY EFFECTS OF PROSTAGLANDIN-F2ALPHA INVIVO

  • 1 January 1979
    • journal article
    • research article
    • Vol. 237  (1) , 16-24
Abstract
Prostaglandin F2.alpha. (PGF2.alpha.) has recently been implicated in the pathogenesis of some diarrhea in man. PGF2.alpha. increased the smooth muscle contractile motility of some gastrointestinal muscles in vitro. The in vivo effects of PGF2.alpha. on bowel smooth muscles are not clearly delineated. The effect of PGF2.alpha. on motility of the small and large intestine was investigated in the anesthetized dog. Six contractile force transducers were implanted to record contractions from both the circular and longitudinal muscles of the duodenum, ileum and colon. Blood pressure was monitored from the femoral artery and drug injections were made in the femoral vein. PGF2.alpha. administration (i.v., 1 .mu.g/kg per min) significantly stimulated duodenal circular muscle contractile frequency while depressing the longitudinal muscle contractile tone. In the ileum, PGF2.alpha. markedly stimulated circular and longitudinal muscle contractions. In the circular ileum, tone was significantly increased while in the longitudinal ileum it was significantly decreased. In the colon PGF2.alpha. did not significantly affect intestinal motility. The diarrheal effects of PGF2.alpha. may be related to an effect on small bowel rather than on large bowel motility in the dog.