The effect of cocaine, desipramine, 6 hydroxydopamine and indomethacin on the sensitivity of the estrogen dominated ampulla of rabbit oviduct to (-) norepinephrine

Abstract

The effect of the adrenergic innervation on the sensitivity of the ampullary portion of rabbit oviduct to (-) norepinephrine has been examined. Tissues were removed from estrogen dominated rabbits and isometric contractions of the longitudinal and circular muscle layers were recorded separately. Longitudinal muscle was significantly more sensitive to added (-) norepinephrine than circular muscle. This difference in sensitivity was reduced by cocaine, desipramine and by 6 hydroxydopamine pretreatment. Blockade of extraneuronal uptake, of catechol O methyl transferase and of prostaglandin synthesis had no significant effect on the responses of either longitudinal or circular muscle to (-) norepinephrine. It is suggested that the difference in sensitivity between the longitudinal and circular muscle layers of the ampulla to (-) norepinephrine is due to a greater concentration of adrenergic nerves present in the circular muscle layer.