Effects of gene knockdown of NF-κB in RVLM on NOS I–PKG or NOS II–peroxynitrite signalling cascade in ventrolateral medulla during Mev intoxication Representative Western blots (insets), or percentage of NOS I, II or III, PKG or NT relative to β-actin protein, detected from the ventrolateral medulla 30 min (Phase I) or 180 min (Phase II) after animals received bilateral microinjection into RVLM of Mev (10 nmol) or aCSF, given 24 h after pre-treatment with double-stranded κB decoy or scrambled (SC) DNA (100 pmol) or their solvent (Veh). Values are mean ± s.e.m. of triplicate analyses, n = 5–6 animals per experimental group. *P < 0.05 vs. Veh + aCSF group, and +P < 0.05 vs. Veh + Mev group in the Scheffé's multiple-range analysis. ND, below detection limit.