The role of antioxidants in models of inflammation: emphasis on L-arginine and arachidonic acid metabolism.

Inflammatory processes are made up of a multitude of complex cascades. Under physiological conditions these processes aid in tissue repair. However, under pathophysiological environments, such as wound healing and hypoxia-ischaemia (HI), inflammatory mediators become imbalanced, resulting in tissue destruction. This review addresses the changes in reactive oxygen species (ROS), L-arginine and arachidonic acid metabolism in wound healing and HI and subsequent treatments with promising anti-oxidants. Even though these models may appear divergent, anti-oxidant treatments are nevertheless still having favourable effects. On the basis of recent findings, it is apparent that protection with anti-oxidants is not solely attributed to scavenging of ROS. In addition, the actions of anti-oxidants must be considered in light of the inflammatory process being assessed. To this end, there does not appear to be any universally applicable single mechanism to explain the actions of anti-oxidants.

A clinical study of low molecular weight-hydroxyethyl starch, a new plasma expander.

1. The pharmacokinetics of a new plasma expander, low molecular weight-hydroxyethyl starch (LMW-HES) were examined in six normovolaemic men. 2. One hour post-infusion, 13.5% of the total dose of LMW-HES injected was excreted in the urine, 50.2% was present in the intravascular space, and 36.3% was unaccounted for. 3. Twenty-four hours post-infusion, 65.5% of the total dose of injected LMW-HES had been excreted in the urine, 4.1% remained intravascularly, and 30.4% was unaccounted for. 4. The plasma volume increased rapidly from a mean value of 45.7 ml kg-1 to a maximum value of 57.9 ml kg-1 immediately post-injection, then gradually returned to normal over 24 h. 5. The infusion of an average of 58.1 g had no effect on ESR, renal and hepatic biochemical indices. 6. LMW-HES appears to be safe and effective, and should be of value clinically when rapid and short-lived augmentation of the plasma volume is required.