DETRIMENTAL EFFECTS ON VILLUS FORM DURING CONVENTIONAL ORAL REHYDRATION THERAPY FOR DIARRHEA IN CALVES - ALLEVIATION BY A NUTRIENT ORAL REHYDRATION SOLUTION CONTAINING GLUTAMINE

This paper examines the possibility that treatment of diarrhoea with c onventional oral rehydration solutions (ORSs) may be detrimental to vi llus structure by imposing nutrient deprivation and that such detrimen tal effects may be reduced or avoided by using a nutrient ORS. A conve ntional WHO-type ORS (W) was compared with two nutrient solutions (N a nd G) both containing high glucose concentrations and the latter conta ining glutamine; their effects on enteric structure were assessed by m orphometric analysis of samples obtained from diarrhoeic calves after 96h treatment. Comparisons were also made with samples from controls a nd diarrhoeic calves at the stage where oral rehydration would have be gun in the treated groups. As in our previous ORS studies, diarrhoea w as induced with enterotoxigenic Escherichia coli (09:K30:K99). We meas ured villus length and width, crypt depth and width and calculated vil lus surface area in proximal, mid and distal small intestine (PSI, MSI , DSI), using standard morphometric techniques. Proximal and distal sp iral colon samples (PC, DC) were examined for crypt depth and width; m itoses per crypt were counted in samples from all regions. Non-diarrho eic calves showed the expected gradient of villus length through PSI, MSI and DSI, hence data for each region are normalized as a percentage of the control value for that region. PSI showed the greatest loss of villus length and surface area (50%) with diarrhoea. In MSI and DSI t he villus loss was greater with solution W and N or G, as were increas ed mitoses and crypt depth. Crypt depth and mitoses also increased in the colon with solution W. Colonic crypt width increased with diarrhoe a and conventional oral rehydration but less so with G; there is reaso n to believe that such changes have functional significance. Crypt cha nges in colon, MSI and DSI were least with solution G. The changes dev eloping in diarrhoeic calves prior to treatment were thus less apparen t in those treated with a nutritional ORS, particularly if it containe d glutamine.