GABAB receptor-mediated contractile effects resistant to tetrodotoxin in isolated cat ileum.
The effects of gamma-aminobutyric acid (GABA) and GABAergic drugs were studied on longitudinal strips from cat terminal ileum prepared after removing the myenteric plexus. GABA and baclofen exerted concentration-dependent contractile effects. Muscimol was ineffective, and bicuculline did not antagonize the effect of GABA. The complete elimination of the neural input to the smooth muscle cells by tetrodotoxin failed to prevent the action of GABA and baclofen. Pharmacological analyses of the effects indicated the existence of GABAB receptors on the smooth muscle cells in the longitudinal layer of cat terminal ileum.
Pencheva
N
N
Institute of Physiology, Bulgarian Academy of Sciences, Sofia.
Venkova
K
K
Radomirov
R
R
D000818:Animals; D001418:Baclofen / Q000494:pharmacology; D001640:Bicuculline / Q000494:pharmacology; D002415:Cats; D004351:Drug Resistance; D007082:Ileum / Q000187:drug effects; D066298:In Vitro Techniques; D008297:Male; D009119:Muscle Contraction / Q000187:drug effects; D009121:Muscle Denervation; D009130:Muscle, Smooth / Q000187:drug effects*; D011963:Receptors, GABA-A / Q000502:physiology*; D013779:Tetrodotoxin / Q000494:pharmacology*; D005680:gamma-Aminobutyric Acid / Q000494:pharmacology
D011963:Receptors, GABA-A; D013779:Tetrodotoxin; D005680:gamma-Aminobutyric Acid; D001418:Baclofen; D001640:Bicuculline