Effects of apocynin treatment of rats in the absence and in the presence of HgCl2 on maximum response (Rmax) and sensitivity (pD2) to phenylephrine.

Parameters of maximal response (Rmax) and sensitivity (pD2) of the concentration-response curves to phenylephrine in aortas from rats untreated, treated with mercury (HgCl2), apocynin and apocynin plus mercury (ApoHg) in intact (Control) and endothelium removal (E-) segments and in the presence of L-NAME (100 µM), Apocynin (0.3 mM) or Indomethacin (1 µM) incubation. Results are expressed as mean±SEM. Rmax, maximal effect (expressed as a percentage of maximal response induced by 75 mM KCl) and pD2 expressed as -log one-half Rmax; t-test: *P#Pvs. Untreated group.