ABSTRACT
The effect of urografin, a contrast medium commonly used for intravenous urography, on the arterial blood pressure and ECG of anaesthetised dogs was studied. In addition the interaction of this agent with some drugs was also investigated. Urografin given i.v as a single shot injection of 1.0 ml/kg produced significant reduction in the systolic, diastolic and mean blood pressure. These changes reached the maximum level 5 minutes after the injection and gradually returned to became completely normal 10 minutes after administration of the agent. However, no changes in the heart rate or any other ECG abnormality could be demonstrated. The hypotensive effect of urografin did not change if the agent was given 15 minutes after prior treatment of the animals with atropine, propranolol, pheneramine salicylate, cimetidine, dexamethasone or combination of pheneramine salicylate and cimetidine. The present study could demonstrate that the hypotension induced by urografin was most probably mediate through a direct action rather than an effect on the muscarinic, beta-adrenergic or histamine receptors or the release of leukotriens