Effect of vasoactive intestinal polypeptide (VIP) on the in vitro and in vivo motility of the rabbit reproductive tract.
Isolated segments of rabbit ampulla and isthmus and strips of uterus and cervix were spontaneously mechanically active in vitro, and this activity was inhibited in a dose-dependent manner by 2 to 200 ng/ml vasoactive intestinal polypeptide (VIP). The oviductal segments were the most inhibited, the uterine strips the least inhibited. These tissues were stimulated to contract in a dose-dependent manner by epinephrine (EPI), with the uterus and cervix being the more responsive. VIP (200 ng/ml) produced only a slight noncompetitive antagonism of this stimulation. Recordings made with miniature force transducers showed the isthmus, uterus, and cervix also to be spontaneously active in vivo. This activity was inhibited by injections (1, 10, and 20 micrograms) and infusions (1.0 and 2.5 micrograms/min) of VIP. The isthmus was the most inhibited, the cervix the least inhibited. Possible physiologic implications of these pharmacologic effects are discussed.
D000818:Animals; D004305:Dose-Response Relationship, Drug; D005260:Female; D005768:Gastrointestinal Hormones / Q000494:pharmacology*; D005836:Genitalia, Female / Q000187:drug effects / Q000502:physiology*; D066298:In Vitro Techniques; D007275:Injections, Intravenous; D009119:Muscle Contraction / Q000187:drug effects*; D009130:Muscle, Smooth / Q000187:drug effects / Q000502:physiology; D011817:Rabbits; D014660:Vasoactive Intestinal Peptide / Q000008:administration & dosage / Q000494:pharmacology*
D005768:Gastrointestinal Hormones; D014660:Vasoactive Intestinal Peptide