Dietary changes improve survival of the cftr s489x homozygous mutant mouse. Eckman, Elizabeth A., Calvin U. Cotton, Dianne M. Kube, and Pamela B. Davis. Departments of Pediatrics, Molecular Biology and Microbiology, and Physiology and Biophysics, Case Western Reserve University, Cleveland, OH 44106
APStracts 2:0110L, 1995.
Over 90% of untreated CFTR S489X homozygous (CF) mutant mice reportedly die by 40 days of age of intestinal obstruction, significantly limiting their usefulness as a model for the human disease. Since the period of highest mortality is during the week following weaning, we hypothesized that providing a low-residue liquid diet would improve survival and growth. When 99 CF mice that survived to 10 days of age were fed Peptamen (Clintec Nutrition), an elemental liquid diet, 88% of them survived to maturity (50 days). The diet causes only minor histologic and ion transport changes in the intestines of normal mice, and does not reduce growth rate or size. CF mice raised on Peptamen continue to display severe pathological changes in the intestine and completely lack a cyclic AMP-inducible chloride current in the cecum. This combination of dietary and bedding changes provides a reliable method for keeping CF mice alive well into adulthood and will be useful for the evaluation of the effect and duration of potential therapies for CF.

Received 22 March 1995; accepted in final form 11 June 1995.
APS Manuscript Number L92-5.
Article publication pending Am. J. Physiol. (Lung Cell. Mol.
Physiology).
ISSN 1080-4757 Copyright 1995 The American Physiological Society.
Published in APStracts on 11 July 1995.