[Effects of selective nitric oxide synthase inhibitor in sheep with endotoxic shock].
OBJECTIVE
To investigate the effects of S-methylisothiourea sulfate (SMT), a selective inducible nitric oxide synthase (iNOS) inhibitor, on hyperdynamic endotoxic shock sheep.


METHODS
Endotoxic shock was induced by Escherichia coli endotoxin in both control (n = 8) and SMT groups (n = 8). SMT was given intravenously. Hemodynamic data, oxygen delivery derived parameters and intramucosal pH (pHi) were measured.


RESULTS
The control group had a hyperdynamic state, similar to that of human septic shock. In the SMT group, blood pressure was maintained at baseline, and cardiac index (CI) was lower than that in the control group (P < 0.05). Oxygen extraction ratio (O2 ext) was increased up to 40% +/- 5% and was much higher than that of the control group (P < 0.01). Pulmonary artery pressure (PAP) was higher than that of the control group (P < 0.01), and pHi decreased gradually similarly to the control group.


CONCLUSIONS
SMT restored the blood pressure and increased O2 extespecially in the gut, but decreased CI and oxygen delivery and increased PAP. So over inhibition of iNOS should be cautiously considered.
Liu
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D
Department of Critical Care Medicine, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Beijing.
Chen
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D
Qiu
H
H
D000818:Animals; D001794:Blood Pressure / Q000187:drug effects; D006439:Hemodynamics / Q000187:drug effects; D007550:Isothiuronium / Q000031:analogs & derivatives* / Q000494:pharmacology / Q000627:therapeutic use; D019001:Nitric Oxide Synthase / Q000037:antagonists & inhibitors*; D010101:Oxygen Consumption; D011897:Random Allocation; D012756:Sheep; D012772:Shock, Septic / Q000188:drug therapy
D007550:Isothiuronium; D019001:Nitric Oxide Synthase; C027744:S-methylisothiopseudouronium