In vivo beta 2-adrenoceptor hyporesponsiveness in the cardiovascular system of the pig after Bordetella pertussis.
The effects of Bordetella pertussis (B. pertussis) on autonomic receptor function were investigated in vivo in the cardiovascular and in particular in the coronary vascular system of the pig. For this purpose the pigs were injected i.p. with B. pertussis vaccine 4 days prior to the experiment. Blood pressure, heart rate, cardiac output, coronary flow, left ventricular pressure and its dP/dt were measured. B. pertussis induced an increase in the baseline values for heart rate, cardiac output, coronary flow and maximal rate of rise of left ventricular pressure (maxLVdP/dt). Left ventricular end diastolic pressure and coronary vascular resistance were decreased. Dose-response curves were made for the beta 2-sympathicomimetic salbutamol. Pretreatment with B. pertussis reduced the effect of salbutamol on LVEDP and maxLVdP/dt. Furthermore, the effects of salbutamol on coronary flow and coronary vascular resistance were nearly completely inhibited. In conclusion, the present in vivo study in pigs evidenced hyporesponsiveness of the coronary and cardiac beta 2-adrenoceptors.
Van Heuven-Nolsen
D
D
Department of Veterinary Pharmacology, University of Utrecht, The Netherlands.
Schoute
E
E
Verdouw
P D
PD
De Wildt
D J
DJ
Nijkamp
F P
FP
D000420:Albuterol / Q000494:pharmacology; D000818:Animals; D002302:Cardiac Output / Q000187:drug effects; D003326:Coronary Circulation / Q000187:drug effects; D005260:Female; D006339:Heart Rate / Q000187:drug effects; D006439:Hemodynamics / Q000187:drug effects*; D008297:Male; D009200:Myocardial Contraction / Q000187:drug effects; D010567:Pertussis Vaccine / Q000494:pharmacology*; D011943:Receptors, Adrenergic, beta / Q000187:drug effects*; D013552:Swine; D014655:Vascular Resistance / Q000187:drug effects
D010567:Pertussis Vaccine; D011943:Receptors, Adrenergic, beta; D000420:Albuterol