[Observation on the effect of vitamin C in alleviating peroxidative damage in gut of dogs during enteral fluid resuscitation of severe burn shock].

OBJECTIVE

To investigate the effect of vitamin C (VC) on alleviating peroxidative damage in gut of dogs during enteral fluid resuscitation of severe burn shock.

METHODS

Eighteen male Beagle dogs were subjected to 50% total body surface area (TBSA) full-thickness burn 24 hours after duodenostomy and cannulation of cervical artery and vein. The dogs were divided into no resuscitation (NR) group (no treatment after burn), enteral resuscitation (ER) group, and ER+VC group according to the random number table, with 6 dogs in each group. Dogs in ER and ER+VC groups were respectively infused with glucose-electrolyte solution (GES) and GES containing 250 mg/kg VC through duodenostomy tube 30 minutes after burn. The infusion rate and volume of GES were in accordance with Parkland formula. Venous blood of dogs was drawn before (0) and at 2, 4, 6, and 8 post burn hours (PBH) to determine the activity of diamine oxidase (DAO) in plasma. Dogs were sacrificed at PBH 8 to collect specimens of jejunum tissue for determining the content of malondialdehyde (MDA), and activity of myeloperoxidase (MPO), xanthine oxidase (XOD) and superoxide dismutase (SOD), and assessment of the water ratio of intestinal tissue by dry-wet weight method.

RESULTS

50% TBSA burn injury resulted in significant elevation of DAO in every group. The activity of DAO in ER group was obviously higher than that in NR group at PBH 6 and 8 (P < 0.05), but DAO activity in ER+VC group was significantly lower than those in the other two groups after PBH 2 (P < 0.05 or P < 0.01). MDA content, MPO and XOD activity and the water ratio of intestinal tissue [(5.74 +/- 0.51) nmol/mg, (2.08 +/- 0.46) U/g, (58.4 +/- 3.8) U/mg, (81.5 +/- 1.8)%] in ER group at PBH 8 was respectively significantly higher than that in NR group [(5.43 +/- 0.25) nmol/mg, (1.55 +/- 0.21) U/g, (50.1 +/- 2.8) U/mg, (78.3 +/- 1.5)%, P < 0.05 or P < 0.01]. While the activity of SOD in ER group (72 +/- 12) U/mg was lower than that in NR group (97 +/- 20) U/mg. MDA content, MPO and XOD activity and water ratio of intestinal tissue in ER+VC group was respectively lower than that in ER group, with activity of SOD in the former group higher than that in the latter group (P < 0.01).

CONCLUSIONS

Vitamin C can alleviate peroxidative damage and tissue edema in gut induced by ischemia and reperfusion, and intestinal complications during oral rehydration during burn shock can be reduced.