Effect of superoxide dismutase on hemorrhagic hypotension and retransfusion-evoked middle cerebral artery endothelial dysfunction

C. Szabo, C. Csaki, Z. Benyo, J. Marczis, M. Reivich, A. G.B. Kovach

Research output: Contribution to journalArticlepeer-review

8 Scopus citations


Middle cerebral artery rings (MCA) were prepared from control and hemorrhagic hypotension and retransfusion-subjected (HHR) cats, with or without superoxide dismutase (SOD) treatment. Two-mm-long MCA segments were suspended in organ chambers containing Krebs-Henseleit solution (37°C, gassed with 95% O2-5% CO2) for isometric force measurements. HHR was produced by bleeding to 90, 70, and 50 mmHg MAP and maintained for 15 rain at each level, followed by retransfusion. HHR resulted in a marked attenuation of the acetylcholine- and ATP-induced endothelium-dependent relaxations of the MCA in vitro. Relaxations induced by the nitric oxide (NO) donor SIN-1 remained unaltered. In vitro treatment of the vessels with SOD (150 U/ml), facilitated the acetylcholine-induced relaxations both in the control arteries and in the vessels after HHR. In the vessel rings from cats that received in vivo SOD (10 mg/kg initial bolus, followed by 0.1-mg/kg/min infusion) during HHR, cholinergic relaxations were more pronounced than in the HHR untreated cats. The ATP-induced relaxations, however, remained attenuated after SOD treatment, except for the highest dose (10-5 M) that was applied. Conclusion: Superoxide release attenuates the endothelium- dependent relaxation by acetylcholine both in control arteries and after HHR in vitro. The protective effect of in vivo SOD treatment on cerebrovascular endothelium-dependent reactivity in cats suggests that superoxide free radicals contribute to the development of the endothelium dysfunction in MCA rings after HHR.

Original languageEnglish (US)
Pages (from-to)104-110
Number of pages7
JournalCirculatory Shock
Issue number3
StatePublished - 1994
Externally publishedYes


  • ATP
  • EDRF
  • SOD
  • acetylcholine
  • cerebral artery
  • endothelium- dependent relaxation
  • reperfusion injury
  • shock
  • smooth muscle
  • superoxide free radical

ASJC Scopus subject areas

  • Cardiology and Cardiovascular Medicine


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