title: GABA modulation of cholinergic transmission in rat oviduct.
abstract: The effects of electrical stimulation, gamma-aminobutyric acid (GABA), acetylcholine (ACh), norepinephrine (NE), 5-hydroxytryptamine (5-HT), GABA agonists and bicuculline were studied on spontaneous movements of isolated rat oviduct. The tissue did not respond to electrical stimulation or to GABA, NE and 5-HT when added to the incubation medium. ACh produced contractions related to its concentration which were maximal at the diestrous-1 phase when GABA caused a 20% rise in the ACh contraction. This effect was mimicked by GABA agonists whereas it was suppressed by bicuculline. beta-Estradiol benzoate (EB) increased ACh contractions in diestrous-1 and in the late proestrous phases. GABA did not modify the EB effect. Progesterone did not modify ACh contractions in any of the studied phases. These findings suggest a possible modulatory role for GABA on ACh responses in the isolated rat oviduct.
mesh_terms: D000109:Acetylcholine / Q000494:pharmacology*; D000818:Animals; D001640:Bicuculline / Q000494:pharmacology; D004558:Electric Stimulation; D004958:Estradiol / Q000494:pharmacology; D005187:Fallopian Tubes / Q000187:drug effects / Q000502:physiology*; D005260:Female; D009119:Muscle Contraction / Q000187:drug effects; D009130:Muscle, Smooth / Q000187:drug effects; D009638:Norepinephrine / Q000494:pharmacology*; D051381:Rats; D011919:Rats, Inbred Strains; D012701:Serotonin / Q000494:pharmacology; D005680:gamma-Aminobutyric Acid / Q000494:pharmacology*
chemical_list: D012701:Serotonin; D004958:Estradiol; D005680:gamma-Aminobutyric Acid; D000109:Acetylcholine; D009638:Norepinephrine; D001640:Bicuculline