The Changes of Serum Amino Acids after Major Burn and Smoke Inhalation Injuries in Rats

Abstract

Objective: The mortality rate of patients with cutaneous combined burns with smoke inhalation injury is reported to be much higher than that of patients with either injury alone. Patients with such combined injury need a more intensive and aggressive nutrition supply to help them survive. The present study was designed to test amino acid flux in cases of combined injury (smoke inhalation injury and cutaneous burns). The purpose was to understand the amino acids flux after such combined injury. Methods: Adult male rats were divided 3 groups, non-injury control, smoke inhalation injury and smoke inhalation injury plus cutaneous burns groups. Rats received smoke inhlalation injury with/without major cutaneous thermal injury (40%BSA). Blood was taken from the tail and storaged along with plasma daily for 5 days. Four different amino acids, glutamate, glutamine, arginine and methionine were tested by HPLC and statistically analyzed. Results: Our preliminary results showed that smoke inhalation injury alone did not cause a significant change in amino acids flux during the first 5 days after injury, and the only increase in arginine was observed on the 3rd day after injury (↑ 27~30%, p＞0.05, non-significant). In the cutaneous burn plus smoke inhalation injury group, all four amino acids decreased immediately and significantly. Conclusions: These results suggest that the four non-essential amino acids (glutamine, glutamate, methionine and arginine) are all conditionally essential amino acids in this combined injury (cutaneous burn plus inhalation injuries). However, in the simple smoke inhalation injury group, the amino acids supply was not as important, at least, in the first 5 days after injury.