In a series of experiments, rats were subjected to end-to-side portacaval shunts using either suture or nonsuture surgical procedures. Rats were maintained on cereal-based or purified diets in pellet form. All rats recovered preoperative body weights within the experimental periods; however, recovery of preoperative body weight was influenced by surgical technique and diet composition. Portacaval shunted rats fed a cereal-based diet required a longer period of time (14 days) to reattain preoperative body weights when compared to portacaval shunted rats fed a purified diet (7 days). Once preoperative body weight was recovered, growth rates of portacaval shunted rats were parallel to those of sham-operated controls. Rats with a suture-portacaval shunt appeared most sensitive to the feeding of a cereal-based diet. All portacaval shunted rats and sham controls fed a purified diet regained preoperative body weights within 7 days after surgery. Sham controls fed either a cereal-based or purified diet recovered preoperative body weights within an average of 4 days. Suture-portacaval shunted rats consuming a pellet form cereal-based diet showed a low feed efficiency which could be reversed by feeding a pellet form purified diet.
Rats subjected to a nonsuture glue-portacaval shunt and fed a cereal-based diet showed 50% lower feed efficiencies than did glue-portacaval shunted rats fed a purified diet. Portacaval shunted rats decreased their consumption of cereal-based diets but not of purified diets postoperatively. These reductions in food intake may be responsible for the growth delays observed in portacaval shunted rats and may explain some of the discrepancies in the literature concerning metabolite determinations since the nutritional and metabolic states of growing and nongrowing animals are not equivalent. From these studies we conclude that the surgical procedure used in the construction of a portacaval shunt as well as the postoperative diet composition are major factors which influence the postoperative performance of the portacaval shunted rat.