Figure 1.

Typical tracings showing the response to H₂O₂ in PHE (10^–6 M)-precontracted mesenteric arteries from WKY and SHR. In the absence of the TP receptor antagonist SQ 29548, H₂O₂ induced a biphasic response: a transient contraction followed by a relaxation in WKY (a) and SHR (b). In the presence of SQ 29548, only the relaxation response was present (c, d). Mean concentration–response relationship for H₂O₂ (in the presence of SQ 29548) and for nitroprusside are given in (e) and (f), respectively (n=4–6 rats). Arteries were denuded of endothelium. ^*P<0.05, ^**P<0.01 compared with respective WKY.