title: Differential effect of pertussis toxin on pre- and postjunctional alpha 2-adrenoceptors in the cardiovascular system of the pithed rat.
abstract: The role of the pertussis toxin-sensitive guanine nucleotide binding regulatory protein in pre- and postjunctional alpha 2-adrenoceptor-mediated responses has been investigated in the pithed rat. Pertussis toxin (50 micrograms/kg i.v., administered 3 days prior to experimentation) markedly inhibited the alpha 2-adrenoceptor-mediated vasopressor response to B-HT 933, but had no effect on the alpha 2-adrenoceptor-mediated cardiac neuroinhibitory effect of B-HT 933. Thus, postjunctional alpha 2-adrenoceptor activation in vascular smooth muscle, but not prejunctional alpha 2-adrenoceptor activation on sympathetic neurons, utilizes a pertussis toxin-sensitive guanine nucleotide binding regulatory protein.
mesh_terms: D000316:Adrenergic alpha-Agonists / Q000494:pharmacology; D000818:Animals; D001381:Azepines / Q000494:pharmacology; D001794:Blood Pressure; D003655:Decerebrate State; D006339:Heart Rate; D008297:Male; D037342:Pertussis Toxin; D051381:Rats; D011919:Rats, Inbred Strains; D011942:Receptors, Adrenergic, alpha / Q000187:drug effects*; D014628:Vagotomy; D010566:Virulence Factors, Bordetella / Q000494:pharmacology*
chemical_list: D000316:Adrenergic alpha-Agonists; D001381:Azepines; D011942:Receptors, Adrenergic, alpha; D010566:Virulence Factors, Bordetella; C015603:azepexole; D037342:Pertussis Toxin