Different mechanisms mediate beta adrenoceptor stimulated vasorelaxation of coronary and femoral arteries
Abstract
"AIM:
To determine whether different mechanisms mediate vasorelaxation of swine coronary and femoral arteries induced by beta adrenoceptor stimulation.
METHODS:
The organ-bath was used to observe the tension changes in rings of coronary and femoral arteries to different concentrations of isoprenaline (ISO) after endothelium removal, nitric-oxide synthase (NOS) inhibition by L-NMMA and beta 1 and/or beta 2 adrenoceptor antagonization.
RESULTS:
Endothelium removal, NOS inhibition, beta 2 adrenoceptor antagonization did not change the vasorelaxation induced by ISO in coronary artery, however, abolished the vasorelaxation in femoral artery. beta 1 Adrenoceptor antagonization did not change the tension of femoral artery, but abolished the ISO induced vasorelaxation of coronary artery.
CONCLUSIONS:
Vasorelaxing effect of ISO in swine coronary artery is mediated through beta 1 adrenoceptor and not through L-arginine/nitric oxide pathway, however, in femoral artery, it is mediated through beta 2 adrenoceptor and L-arginine/nitric oxide pathway."
Keywords:
To determine whether different mechanisms mediate vasorelaxation of swine coronary and femoral arteries induced by beta adrenoceptor stimulation.
METHODS:
The organ-bath was used to observe the tension changes in rings of coronary and femoral arteries to different concentrations of isoprenaline (ISO) after endothelium removal, nitric-oxide synthase (NOS) inhibition by L-NMMA and beta 1 and/or beta 2 adrenoceptor antagonization.
RESULTS:
Endothelium removal, NOS inhibition, beta 2 adrenoceptor antagonization did not change the vasorelaxation induced by ISO in coronary artery, however, abolished the vasorelaxation in femoral artery. beta 1 Adrenoceptor antagonization did not change the tension of femoral artery, but abolished the ISO induced vasorelaxation of coronary artery.
CONCLUSIONS:
Vasorelaxing effect of ISO in swine coronary artery is mediated through beta 1 adrenoceptor and not through L-arginine/nitric oxide pathway, however, in femoral artery, it is mediated through beta 2 adrenoceptor and L-arginine/nitric oxide pathway."