Interrelationships between diet and weight gain in rats with portacaval shunts

¹ Department of Physiology, School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania

Rate of weight gain and daily food intake, as well as fasting colon weight, liver weight, and arterial blood ammonia levels, were measured in rats with end-to-side portacaval anastomoses and their sham-operated, paired controls. The diets provided were regular chow and special, low-residue feed with increased amounts of protein, fat, or carbohydrate. The chow-fed, operated group gained weight at a significantly slower rate than their paired controls which was the only significant intragroup difference. The special-diet, operated groups gained significantly slower than the shams when the data from these groups were pooled, obliterating the dietary distinction. This singularity of the chow-fed group was accompanied by a very much heavier colon in both operated and control categories than that of animals receiving low-residue feed. Liver weights were lower and arterial ammonia levels higher in animals with shunts. The significance of the greater colon weight and lower rate of weight gain in fistulated animals receiving regular chow is discussed in the context of symbiotic relations between gastrointestinal flora and host.

Key Words: shunt encephalopathy • Eck fistula • rat gastrointestinal flora • portal blood ammonia levels

Submitted on July 2, 1963