Pertussis toxin does not affect the adenosine-induced inhibition of the efferent function of cardiac capsaicin-sensitive nerves.
The negative inotropic effect of adenosine (1-100 microM) was abolished in isolated guinea-pig atria obtained from pertussis toxin-pretreated guinea pigs electrically driven at 4 Hz. However, the inhibitory effect of the same concentrations of adenosine on the cardiac response to stimulation of non-adrenergic non-cholinergic (NANC), capsaicin-sensitive sensory nerves, was not modified by the toxin. These results suggest that, while pertussis toxin-sensitive G proteins are involved in the negative inotropic effect of adenosine, they do not mediate the inhibitory effect of adenosine on cardiac NANC neurotransmission.
Mantelli
L
L
Department of Pharmacology, University of Florence, Italy.
Amerini
S
S
Rubino
A
A
Ledda
F
F
D000241:Adenosine / Q000037:antagonists & inhibitors* / Q000494:pharmacology; D000818:Animals; D001341:Autonomic Nervous System / Q000166:cytology / Q000187:drug effects; D002211:Capsaicin / Q000494:pharmacology*; D004558:Electric Stimulation; D019204:GTP-Binding Proteins / Q000378:metabolism; D006168:Guinea Pigs; D006321:Heart / Q000187:drug effects / Q000294:innervation*; D008297:Male; D009476:Neurons, Efferent / Q000187:drug effects*; D037342:Pertussis Toxin; D010566:Virulence Factors, Bordetella / Q000494:pharmacology*
D010566:Virulence Factors, Bordetella; D037342:Pertussis Toxin; D019204:GTP-Binding Proteins; D000241:Adenosine; D002211:Capsaicin