Abstract
In the presence of prazosin and propranolol, electrical transmural stimulation of isolated dog mesenteric artery produced a sympathetic purinergic contraction, which was followed by a relaxation in PGF2α-contracted arteries. Such purinergic responses were mimicked by brief exposure to α, β-methylene ATP (α, β-Me ATP) and were completely inhibited after desensitization of P2x-purinergic receptors. However, exogenous ATP predominantly evoked a relaxation in PGF2α-contracted artery. These results suggest that the sympathetic purinergic response may be caused by a P2x-purinergic receptor-selective mechanism or substance, rather than ATP.
