Liver glycogen after portacaval shunt in rats

Theories to explain the metabolic effects of portacaval shunt (PCS) have frequently failed to take into account the sequelae of PCS-induced anorexia. In this study PCS rats, followed up to 42 days postoperatively, had a lower food intake than ad libitum-fed (ALC) controls and also lost 10% body wt compared to a 20% gain of ALC rats. Liver weight was significantly reduced in PCS rats compared to ALC rats, pair-fed sham-operated (S) and pair-fed normal control (PFC) rats. However, liver glycogen was equally reduced in all animals with reduced food intake (PCS, S, and PFC rats) compared to ALC rats. Plasma glucose was significantly lower in PCS rats and PCS rats had markedly elevated plasma glucagon and lower plasma insulin concentrations than ALC rats, with the result that they had a low insulin: glucagon molar ratio of 1.3:1 compared to 10.2:1 in the ALC rats. The pair-fed control groups had intermediate I:G ratios and plasma glucose concentrations, thus an inverse relationship between mean plasma glucose and mean I:G ratio for each group was found, suggesting that the blood glucose concentration was the primary event determining the I:G ratio for each group.These controlled experiments indicate that hepatic atrophy after PCS appears to be directly related to the shunting of portal blood away from the liver, while reduced liver glycogen is related to decreased food intake. Reduction in total body weight, relative hypoglycemia, and elevated I:G ratios appear to be due to a combination of factors.