OBJECTIVETo investigate the pathogenesis of gastrointestinal motility dysfunction as a result of scald and lipopolysaccharide (LPS) challenge in guinea pigs.

METHODSThirty guinea pigs were enrolled in the study and were randomly divided into 3 groups:i. e. control (n = 10, with intraperitoneal injection of isotonic saline), scald (n = 10, with 30% TBSA deep partial thickness burn) and LPS (n = 10, with intraperitoneal injection of LPS) groups. Thirty minutes after treatment, all animals were gavaged with carbolic ink. The propelled distance of the ink within the gastrointestinal tract was measured. The intestinal tissue was harvested and homogenized, and the contents of CGRP, Na+-K+-ATP enzyme, Mg2+-ATP enzyme, Ca2+-ATP enzyme, Ca2+-Mg2+-ATP enzyme were determined, and the delta phim of haustra coli smooth muscular cell mitochondria was assessed.

RESULTSThe propelled distance of the ink in the gastrointestinal tract in scald (53 +/- 9 cm) and LPS (91 +/- 10 cm) groups was obviously shorter than that in control group (142 +/- 11 cm, P < 0.01). Furthermore, the distance in scald group was shorter than that in LPS group (P < 0.01). The CGRP content in scald and LPS groups [52.0 +/- 39.0 microg/L and 20.0 +/- 23.0 microg/L] was obviously higher than that in control group (0.8 +/-2.0 microg/L, P <0.05 or 0.01), especially in scald group ( P < 0.05). The Na+-K+-ATP enzyme, Mg2+-ATP enzyme, Ca2+-ATP enzyme, Ca2+-Mg2+-ATP enzyme and the delta phim in scald and LPS groups were remarkably lower than those in control group (P <0.005), but there was no difference between scald and LPS groups (P > 0.05).

CONCLUSIONThe gastrointestinal motility of guinea pigs could obviously be inhibited by scald and LPS, especially by scald. LPS might be the key factor to produce change in the membrane potential of mitochondria of intestinal smooth muscle after severe scald.