TOPICAL D-MYO-INOSITOL-1,2,6-TRISPHOSPHATE AND HEXYLBETAINE TREATMENTREDUCES ALBUMIN EXTRAVASATION IN EXPERIMENTAL RAT SKIN BURN INJURY

The anti-inflammatory agent D-myo-inositol-1,2,6-trisphosphate (1,2,6- IP3) has shown beneficial effects in experimental burns following syst emic administration. The purpose of this study was to investigate the effect of topical 1,2,6-IP3 cream on a standardised full-thickness 1 c m(2) burn injury in rats. The experimental cream contained a transcuta neous absorption enhancer, hexylbetaine. Five different treatment grou ps were used. Two experimental groups of burned rats received either 1 ,2,6-IP3 cream with hexylbetaine (n = 10) or without hexylbetaine (n = 10). Two burned control groups were treated either with hexylbetaine cream (n = 10) or placebo cream (n = 10), while a third control group was untreated (n = 14). The various creams (0.5 g) were administered t o the experimental burn area and allowed to remain for 3 h covered wit h an occlusive dressing. Spectrophotometrical quantification of Evans blue albumin extravasation was used to evaluate the effect of the expe rimental creams on vascular permeability following the burn trauma. Re sults showed a significant reduction of albumin extravasation both by 1,2,6-IP3 (p<0.05) and by hexylbetaine alone (p<0.01), as compared to placebo cream-treated animals. The transcutaneous absorption enhancer hexylbetaine did not further improve the effect of 1,2,6-IP3 on burn o edema. In conclusion, both topical 1,2,6-IP3 and hexylbetaine induced a significant reduction of albumin extravasation in burned skin. The e ffect of 1,2,6-IP3 could be related to previously shown anti-inflammat ory actions of the agent, while the mechanisms of actions of hexylbeta ine remain to be investigated. (C) 1998 Elsevier Science Ltd for ISBI. All rights reserved.