Role of sulfur dioxide in acute lung injury following limb ischemia/reperfusion in rats.

Sulfur dioxide (SO2) is naturally synthesized by glutamate-oxaloacetate transaminase (GOT) from L-cysteine in mammalian cells. We aim to investigate the role of SO2 in inflammation in acute lung injury (ALI) following limb ischemia/reperfusion (I/R). Male Wistar rats were subjected to limb I/R and were injected with saline, GOT inhibitor hydroxamate (HDX, 0.47 mmol/kg), or the SO2 donor Na2 SO3 /NaHSO3 (0.54 mmol/kg/0.18 mmol/kg). Compared with the sham operation, the plasma SO2 levels were significantly decreased by limb I/R treatment. In addition, SO2 concentration and GOT activity in the lung tissue were also reduced in ALI. The occurrence of ALI following limb I/R can be prevented by Na2 SO3 /NaHSO3 treatment, whereas it can be significantly aggravated by HDX. The plasma IL-1ß, IL-6, and IL-10 levels were consistent with myeloperoxidase activity and inflammation in lung tissue. In conclusion, our data suggest that downregulation of endogenous SO2 production might be involved in pathogenesis of ALI following limb I/R in rats.