Cholera toxin and vibrio in the adult rat intestinal loop
Akhter, M.H.; Sabir, M.; Srinivas, R.V.; Mohapatra, L.N.; Bhide, N.K.
Indian Journal of Physiology and Pharmacology 23(2): 68-76
1979
ISSN/ISBN: 0019-5499 PMID: 489099 Document Number: 144934
Like rabbit, rat manifests fluid accumulation in its ligated small intestinal loop in response to cholera toxin. The details of this phenomenon are studied. Fasting for 24-27 h is adequate. Rats fasting on ad lib 5% glucose water lose less body weight than those on plain water. Older rats are sensitive like the 40 day old rats. Pentobarbitone is more convenient and permits prolonged anesthesia. Irrigation of intestine is not necessary and 30 cm length of loop is optimum. Jejunal and ileal portions of the small intestine are about equally sensitive. Only one 30 cm long loop of intestine should be prepared per rat. Loop responds to toxin dose range 10-30 mg. Five h is the optimum period for fluid collection. The fluid volume is not related to sex but to body weight; rats of narrow weight range should be used. Electrolyte composition of the loop fluid (unlike its volume) remains remarkably constant. Heat-inactivated cholera toxin, cholera vaccine, staphylococcal toxin, Syncase medium, peptone or prostaglandin E1 do not cause fluid accumulation. The rat loop method can be conveniently used for bioassay and other study of cholera toxin, vaccine and anti-cholera drugs. Live cholera vibrio (6.25 .times. 109) injected into 30 cm intestine loop of fasting adult rats also produced fluid accumulation in 18 h (but less in 12 h). The rat is sensitive to cholera toxin but less to live Vibrio, whereas rabbit is sensitive to both.