Distribution of blood flow to the gastrointestinal tract of swine during T-2 toxin-induced shock

Abstract

Swine (6 per group) were used to study gastrointestinal blood flow during T-2 toxin-induced shock. Low- and high-dose groups were given T-2 toxin at 0.6 or 2.4 mg/kg via the pulmonary artery; controls were given the ethanol vehicle. Radiolabeled microspheres were administered into the left atrium to assess organ blood flow predosing and at 90-min intervals for 6 hr. Gastric blood flow decreased in both T-2 groups, and at 6 hr the high-dose group's value was 17% of the predose value. In the low-dose group, the lowest gastric blood flow (30% of predose) was observed 3 hr postdosing. Small-intestinal blood flow of the control group declined to 64% of the predose value. In the high-dose group, small-intestinal blood flow at 3 hr was 174% of predose, followed by a reduction to 62% at 6 hr, coinciding with a severe decline in cardiac output. Small-intestinal blood flow of the low-dose group was 159% of predose at 1.5 hr, then declined to the control value. The high-dose group's large-intestinal blood flow increased to 177% of predose at 3 hr, then declined to 66% at 6 hr. The low-dose group's large-intestinal blood flow increased to 200% of the predose value. The severe decline in gastric blood flow is probably related to the development in swine (given high doses of T-2 toxin) of a grossly bright red gastric fundus, with histologic evidence of vascular congestion and mucosal deterioration. The initial increase in blood flow to the intestine may contribute to its tolerance to sublethal doses of T-2 toxin and may facilitate the rapid intestinal absorption of the toxin.