Renal vasodilatation induced by DOI, a 5-HT2 receptor agonist, in the canine kidney.

An intrarenal infusion of (+/-)-1-(2,5-dimethoxy-4-iodophenyl)-2-aminopropane (DOI), a selective 5-HT2 agonist, at a rate of 5 micrograms/min in anesthetized dogs resulted in an increase in renal blood flow (RBF) without any transient decrease as usually observed during the infusion of 5-HT. During the infusion, urine flow (UF) and urinary sodium excretion rates (UNaV) increased along with RBF while the mean arterial pressure and glomerular filtration rate did not change. After pretreatment with ritanserin, a selective 5-HT2 antagonist, DOI failed to increase RBF, UF and UNa V. It is concluded that DOI produces renal vasodilatation mediated via 5-HT2 receptors and has a diuretic action.