1. We have investigated the role of neuropeptide Y (NPY) in sympathetic vasoconstriction and its possible contribution to de creased mesenteric vasoconstrictor responses to electrical field stimulation (EFS) in pregnancy in vivo using an in situ blood-perfused mesenteric preparation in 18-20 day pregnant and age-matched non-pregnant Wistar-Kyoto (WKY) rats.2. Mean blood pressure (BP) was decreased in pregnant compared with non-pregnant rats. Mesenteric basal perfusion pressure (PP) was not significantly reduced in pregnancy. BIBP 3226, a specific NPY Y-1 receptor antagonist, did not affect mean BP or mesenteric basal PP in pregnant or non-pregnant animals.3. Mesenteric vasoconstrictor responses to EFS were blunted in pregnant compared with non-pregnant controls. BIBP 3226 significantly suppressed mesenteric vasoconstrictor responses to EFS in both pregnant and non-pregnant animals. Decreased mesenteric responses to EFS in pregnancy were still evident following NPY Y-1 receptor blockade.4. These results suggest that endogenous NPY plays a role in rat mesenteric sympathetic vasoconstriction in vivo. However, NPY is unlikely to be responsible for the impairment of EFS-induced mesenteric vasaconstriction in pregnant WKY rats.
|Journal||Clinical and Experimental Pharmacology and Physiology|
|Publication status||Published - 1998|