A Novel Adipocytokine, Omentin, Inhibits Agonists-induced Increases of Blood Pressure in Rats

Omentin is a recently identified adipocytokine, and we previously demonstrated that omentin played anti-inflammatory roles in vascular endothelial and smooth muscle cells. We also demonstrated that omentin induced vasodilation in rat isolated blood vessels. However, effects of omentin on blood pressure (BP) are not determined. Here, we examined whether intravenously injected omentin acutely alters BP of Wistar rats. Omentin (0.06-18 μg/kg) alone did not alter BP of Wistar rats. On the other hand, omentin (18 μg/kg) significantly inhibited noradrenaline (NA; 2 μg/kg)-induced increases in systolic BP and mean BP. Omentin (18 μg/kg) significantly inhibited angiotensin II (1 μg/kg)-induced increases in diastolic BP. Omentin (18 μg/kg) significantly inhibited dimorpholamine (3 mg/kg)-induced increases in diastolic BP. Omentin (18 μg/kg) failed to inhibit the NA (0.02-2 μg/kg)-induced increases of systolic BP in the nitric oxide (NO) synthase inhibitor, N(G)-nitro-l-arginine methyl ester (80 mg/kg, 1 day)-treated Wistar rats. In summary, we for the first time demonstrated that omentin inhibited agonists-induced increases in BP. The effect of omentin was suggested to be mediated likely via NO-dependent mechanism.