Is there a role for dopamine in the regulation of motility of sow oviducts?
Dose-response curves for norepinephrine (NE), dopamine (DA) and 2-bromo-alpha-ergocryptine (BEC) in the isthmic and ampullary regions isolated from proestrous sow oviducts, were drawn. NE, DA and BEC depressed the contractile activity of ampullary segments in dose-dependent fashion. In the isthmic region, NE induced a dose-related stimulation whereas DA and BEC evoked relaxation. Propranolol (10(-6)M) did not modify significantly the effect of DA on the ampulla, whereas spiperone, chlorpromazine and haloperidol, shifted to the right DA dose-response curves. Haloperidol and spiperone were able to partially antagonize responses to DA of the isthmus. The catecholamine contents of the ampullary (a) and isthmic (i) regions of sow oviducts during proestrus (P), estrus (E) and metestrus (M) proved to be quite different and differently affected by the variations of the sex cycle: NE, DA and epinephrine (EPI) in (i) higher than in (a); NE in (i) and (a) during M higher than during E; NE in (i) lower during E than during P. The probable presence of specific dopamine receptors in sow oviducts as well as their eventual role in modulating tubal motility are discussed in this paper.
D000818:Animals; D004298:Dopamine / Q000502:physiology*; D005187:Fallopian Tubes / Q000502:physiology*; D005260:Female; D013552:Swine
D004298:Dopamine