Effects of Veratrum nigrum alkaloids on central catecholaminergic neurons of renal hypertensive rats

To study the central hypotensive mechanism of Veratrum nigrum L var ussurience Nakai alkaloids (VnA) in renal hypertensive rats(RHR).The quantitative method of immunocytochemistry (ICC) was used to observe and detect the effect of VnA (30 micrograms.kg-1, i.v.) on activity of central catecholaminergic (CA) neurons of C1, C2, A1, and A5 areas in RHR.VnA increased the immunoreactivity (IR) of tyrosine 3-monooxygenase (TM)-immunopositive (IP) neurons of C1, C2, and A5 areas in RHR experimental group compared with RHR control group [positive units: (1.9 +/- 0.4), (1.18 +/- 0.23), (1.2 +/- 0.4) vs (0.15 +/- 0.22), (0.31 +/- 0.16), (0.69 +/- 0.20), respectively]; IR of TM-IP neurons of C1 and C2 areas in RHR control group was decreased compared with sham-operated group [positive units: (0.15 +/- 0.22), (0.31 +/- 0.16) vs (1.45 +/- 0.29), (1.36 +/- 0.25), respectively].VnA increased the activity of central CA neurons in RHR to exert its hypotensive effect.