Role of defunctionalized bowel in jejunoileal bypass-induced liver disease in rats.

The pathogenesis of jejunoileal bypass-induced liver disease was investigated in the rat model. Male Sprague-Dawley rats were subjected to 90% jejunoileal bypass and compared to rats having undergone 90% jejunoileal resection, to ad libitum and pair-fed controls and to weight-matched (underfed) controls. After 8 weeks the animals were killed and selected analyses performed. Several indications of liver dysfunction were observed in the bypass rats including hepatomegaly, hypotriglyceridemia, hypoproteinemia, elevated SGOT levels, and markedly decreased levels of cytochrome P-450. All of these abnormalities with the exception of elevated SGOT levels and decreased serum proteins were not observed to the same degree in animals in which the defunctionalized bowel was resected. Rats which were underfed (weight matched) did not develop any of the abnormalities of liver injury demonstrated in the bypass rats. Multiple factors appear to be responsible for the production of bypass-induced liver disease, but the defunctionalized bowel plays an important role.