Clonidine-induced desensitization differentiates presynaptic alpha-2 adrenoceptors of the guinea-pig ileum and rat vas deferens
- PMID: 2992403
Clonidine-induced desensitization differentiates presynaptic alpha-2 adrenoceptors of the guinea-pig ileum and rat vas deferens
Abstract
Clonidine-induced inhibitions of twitch responses of coaxially stimulated guinea-pig ileum and transmurally stimulated rat vas deferens were antagonized by yohimbine in a competitive manner. In contrast to rat vas deferens, clonidine caused desensitization of presynaptic alpha 2-adrenoceptors on cholinergic neurons of guinea-pig ileum. Cross desensitization was observed between clonidine and oxymetazoline. No cross desensitization between clonidine and morphine was observed and indicates that presynaptic alpha 2-adrenoceptors are involved in clonidine-induced desensitization of the presynaptic site in the guinea-pig ileum.
Similar articles
-
Prejunctional inhibitory alpha-adrenoceptors and dopaminoceptors of the rat vas deferens and the guinea-pig ileum in vitro.Eur J Pharmacol. 1979 Sep 15;58(2):189-95. doi: 10.1016/0014-2999(79)90011-6. Eur J Pharmacol. 1979. PMID: 227701 No abstract available.
-
Receptor interactions of a series of imidazolines: comparison of the alpha 2-adrenoceptors between the rabbit vas deferens and guinea pig ileum.Jpn J Pharmacol. 1987 Jun;44(2):171-8. doi: 10.1254/jjp.44.171. Jpn J Pharmacol. 1987. PMID: 2821305
-
Pharmacological characterization of the presynaptic alpha-adrenoceptors regulating cholinergic activity in the guinea-pig ileum.Br J Pharmacol. 1978 Oct;64(2):293-300. doi: 10.1111/j.1476-5381.1978.tb17303.x. Br J Pharmacol. 1978. PMID: 30507 Free PMC article.
-
Sgd 101/75: a sympathomimetic that can be used to identify a new subtype of alpha-adrenoceptor, the alpha 1s-adrenoceptor.Methods Find Exp Clin Pharmacol. 1983 Sep;5(7):425-34. Methods Find Exp Clin Pharmacol. 1983. PMID: 6142147 Review.
-
Subtype classification of presynaptic alpha 2-adrenoceptors.Gen Pharmacol. 1993 Jan;24(1):1-8. doi: 10.1016/0306-3623(93)90003-g. Gen Pharmacol. 1993. PMID: 8387042 Review.
Cited by
-
Effect of clonidine, nimodipine and diltiazem on the in vitro opioid withdrawal response in the guinea-pig ileum.Br J Pharmacol. 1990 Dec;101(4):958-60. doi: 10.1111/j.1476-5381.1990.tb14187.x. Br J Pharmacol. 1990. PMID: 2085717 Free PMC article.
-
Pre- and postjunctional adrenoceptor types in the circular muscle of the guinea-pig caecum.Naunyn Schmiedebergs Arch Pharmacol. 1987 Jul;336(1):37-47. doi: 10.1007/BF00177749. Naunyn Schmiedebergs Arch Pharmacol. 1987. PMID: 3627290