Hemodynamic effect of norepinephrine and serotonin with and without indomethacin

Injections of serotonin (5-HT) into the aortic arch of rats caused greater reductions of blood pressure (BP) and less increases in renal vascular resistance (RVR) than that into jugular veins, in contrast to norepinephrine (NE) which tended to cause larger increases in BP and RVR by the intra-aortic route. Indomethacin (INDO) enhanced renal vasoconstrictor responses to NE, but did not affect those of 5-HT. These data support a central nervous system (CNS) hypotensive effect of 5-HT not shared by NE, and a less interaction with vasodilator prostaglandins for 5-HT, when compared with NE.