Fig. 3. Acetylcholine-induced relaxation of aortic rings from Sham, Shock, and Resuscitated groups anesthetized with isoflurane (  A and  C ) or isoflurane with adjunct nitrous oxide (  B and  D ), and in the absence of indomethacine (  A and  B ) or presence of indomethacine (  C and  D ). Concentration-response curves of Sham groups (  closed circle ), Shock groups (  open circles ) and Resuscitated groups (  triangular up ) are expressed as percentage of preconstriction value to phenylephrine (0.1 mm) and are presented as mean ± SD. INDO = indomethacine; ISO = isoflurane; N²O = nitrous oxide.