Neuropeptide Y and nitrite levels in preeclamptic and normotensive gravid women

OBJECTIVES: Vascular tone is controlled largely by the sympathetic nervous system and is modulated by neuropeptide Y. Preeclampsia is linked to sympat hetic overactivity. Nitric oxide can cause vasorelaxation of vessels or dec rease sympathetic outflow by activating the baroreceptor reflex. Our purpos e in this study was to compare serum levels of neuropeptide Y and nitrite l evels in normotensive and preeclamptic gravid women. STUDY DESIGN: Twelve preeclamptic and 12 normotensive women matched for rac e, body mass index, parity, and gestational age were studied. Neuropeptide Y was measured by using a commercial radioimmunoassay. Nitric oxide was con verted to nitrite by using metallic cadmium, and nitrite levels were determ ined spectrophotometrically by using a colorimetric assay. Data are present ed as mean +/- SEM and were compared by using a t test. RESULTS: Neuropeptide Y levels were similar among preeclamptic and normoten sive gravid women (33.8 +/- 3.0 and 32.2 +/- 3 pg/mL, respectively). Simila rly, there were no differences in nitrite concentrations between preeclampt ic and normotensive patients (11.6 +/- 0.8 vs 11.2 +/- 0.4 mu mol/L, respec tively). We also examined the ratios of neuropeptide Y and nitrite and foun d no correlation between preeclamptic and normotensive women. CONCLUSION: Peripheral levels of neuropeptide Y or nitrite do not correlate with preeclampsia. Assessment of sympathetic overactivity in preeclampsia requires an alternate model.