Effect of lidamidine-HCl on Escherichia coli heat-stable enterotoxin-induced jejunal water and electrolyte secretion in neonatal piglets.

Neonatal piglets were anesthetized, and two jejunal loops, 20 cm in length, were prepared. Then, either water or 0.12, 0.25, 0.5 or 1.0 mg/kg of lidamidine-HCl was injected intraduodenally on a randomized basis, one treatment per pig. Following this, a crude heat-stable enterotoxin (ST) preparation produced from E. coli no. 1261 was injected into the proximal jejunal loop, and trypticase soy broth (TSB) (with osmolality adjusted to equal the enterotoxin preparation) was injected into the distal jejunal loop. Piglets remained anesthetized for 3 h and were then killed. Fluid was collected from the loops for measurement of volume and Na, K and Cl concentration. Empty loop lengths were measured. There was a significant dose-related reduction of volume and Cl content, and a dose-related, but not significant, reduction in Na content in St-treated loops. A comparison of the mean differences in responses between toxin- and TSB-treated loops indicated that the major 'counter-toxic' effect of the lidamidine was a dose-related increase in water and electrolyte absorption.