Evidence against prostaglandin modulation of cardioaccelerator nerve activity in the anesthetized dog.
The hypothesis that prostaglandins have a modulatory role in adrenergic neurotransmitter release was tested in the anesthetized dog. Inhibition of prostaglandin synthesis with indomethacin (10 mg/kg, i.v.) did not alter positive chronotropic responses to cardioaccelerator nerve stimulation or blood pressure responses to exogenous norepinephrine. In the presence of indomethacin, infusions of PGE, (0.01 and 0.1 microgram kg-1 min-1) also failed to influence the responses to cardioaccelerator nerve stimulation although the blood pressure responses to exogenous norepinephrine were reduced in a dose-related manner. It was concluded that endogenous prostaglandins and exogenous PGE2, the purported physiological inhibitor of neurotransmitter release in cardiac tissue, do not play a role in modulating chronotropic responses during cardioaccelerator nerve stimulation in the anesthetized dog.
D000818:Animals; D001794:Blood Pressure / Q000187:drug effects; D004285:Dogs; D005260:Female; D006339:Heart Rate / Q000187:drug effects*; D007213:Indomethacin / Q000494:pharmacology; D008297:Male; D009638:Norepinephrine / Q000494:pharmacology; D010646:Phentolamine / Q000494:pharmacology; D011453:Prostaglandins / Q000502:physiology*; D011458:Prostaglandins E / Q000494:pharmacology; D009435:Synaptic Transmission / Q000187:drug effects*
D011453:Prostaglandins; D011458:Prostaglandins E; D009638:Norepinephrine; D007213:Indomethacin; D010646:Phentolamine