Transport of water and electrolytes by rotavirus-infected mouse intestine: a time course study

The movement of water and transport of Na+ and Cl- by mid-small intestine (M-SI) of rotavirus-infected neonatal mice was investigated by an in vitro perfusion technique. The concentrations of Na+, K+, and Cl- in the luminal contents of upper, middle, and lower small intestine and colon of infected mice were determined by flame photometry (Na+, K+) and an ion selective microelectrode (Cl-). In M-SI, maximal disturbance of water transport occurred at 72 h postinfection (PI): Infected tissue exhibited net water secretion. Water transport was also impaired at 144 h PI. Net secretion of Cl- occurred at 72 h PI, with some evidence of a second phase of reduced magnitude at 120-144 h PI. The magnitude and statistical significance of changes in Na+ transport were both less than those for Cl-, but the pattern of change was similar to that for Cl-. Luminal concentrations of Na+ were elevated between 48 and 144 h PI in the small intestine; this was particularly so in distal regions. Luminal Cl- concentration was maximally elevated to a considerable degree at 72 h PI and remained high at 96 h PI throughout the small intestine; thereafter, Cl- concentration returned to near normal. K+ concentration was unchanged in the small intestinal lumen; in the colon, however, K+ concentrations were depressed 72-168 h PI. In the light of previous data from this laboratory, the present data are interpreted as evidence for a secretory component in rotavirus-induced diarrhea.