Alpha 2-adrenoceptors not imidazole receptors mediate depression of a sacral spinal reflex in the cat.
In chloralose-anaesthesized cats, clonidine, an alpha 2-adrenoceptor agonist with an imidazole ring, depressed pudendal nerve reflex activity. Clonidine's inhibitory action on this compound action potential response was mimicked by guanabenz, a non-imidazole alpha 2-adrenoceptor agonist, and was reversed by SK & F 86466, a non-imidazole alpha 2-adrenoceptor antagonist. These results imply that clonidine's action on this reflex related to urinary sphincter function is mediated by alpha 2-adrenoceptors and is not dependent on an imidazole structure.
Department of Pharmacology, Dalhousie University, Halifax, Nova Scotia, Canada.
J W
JW
Downie
M J
MJ
Espey
J B
JB
Gajewski
D000200:Action Potentials / Q000187:drug effects; D000317:Adrenergic alpha-Antagonists / Q000494:pharmacology; D000818:Animals; D001552:Benzazepines / Q000494:pharmacology; D002415:Cats; D003000:Clonidine / Q000494:pharmacology; D005260:Female; D006143:Guanabenz / Q000494:pharmacology; D054755:Imidazoline Receptors; D008297:Male; D011942:Receptors, Adrenergic, alpha / Q000502:physiology*; D011955:Receptors, Drug / Q000502:physiology*; D012018:Reflex / Q000502:physiology*; D013116:Spinal Cord / Q000502:physiology*; D015016:Yohimbine / Q000494:pharmacology
D000317:Adrenergic alpha-Antagonists; D001552:Benzazepines; D054755:Imidazoline Receptors; D011942:Receptors, Adrenergic, alpha; D011955:Receptors, Drug; D015016:Yohimbine; D006143:Guanabenz; D003000:Clonidine; C039139:benalfocin