A comparison of some renal and cardiovascular effects of a prostaglandin analog, SKF 82526 and ibopamine in anesthetized dogs.

The effects of 0.01 to 40 micrograms/kg i.v. of a novel prostaglandin (PG) analog, (+)-4-[3-[3-[2-(1-hydroxycyclohexyl)ethyl]-4-oxo-2 -2-thiazolidinyl]-propyl] benzoic acid, on hemodynamic and renal functions were compared to those of the dopamine agonists SKF 82526 (0.01 to 400 micrograms/kg i.v.) and ibopamine (10-1000 micrograms/kg i.v.) in anesthetized dogs. The PG analog was the most potent renal vasodilator, maximally increasing renal blood flow (RBF) by 220 +/- 52 ml/min at 20 micrograms/kg i.v. SKF 82526 (40 micrograms/kg i.v.) and ibopamine (1000 micrograms/kg i.v.) elevated RBF by 125 +/- 18 and 74 +/- 31 ml/min, respectively. Both the PG analog and SKF 82526 significantly reduced renal vascular resistance (RVR) and were hypotensive, especially at the higher doses. In contrast, ibopamine dramatically increased mean arterial pressure (MAP) by 140 +/- 13 mm Hg at 1000 micrograms/kg i.v. Lower aortic blood flow (LAF), glomerular filtration rate (GFR), urine flow and fractional excretion rates of sodium, potassium and chloride were not altered during the 15-min period following administration of each dose of each of the compounds. The RBF and depressor responses to the PG analog and to SKF 82526 were not substantially influenced by the alpha-adrenergic antagonist, phenoxybenzamine (POB), while the pressor effect of ibopamine was reversed and dilation of the renal and hindlimb vascular beds was unmasked. The PG analog, the most potent of the three vasodilators studied, exhibited a high degree of renal specificity.