Effect of insulin-like growth factor I on in vivo intestinal absorption ofD-galactose in cirrhotic rats

Insulin-like growth factor I (IGF-I) bioavailability is reduced in liver ci rrhosis, a condition frequently associated with malnutrition. We have analy zed in vivo absorption of D-galactose by jejunal loops in rats with CCl4-in duced liver cirrhosis and the influence of IGF-I on intestinal sugar transp ort in this disease. Two different study protocols were followed. In protoc ol 1, healthy control rats or cirrhotic rats received saline or IGF-I (2 mu g.100 g body wt(-1) day(-1)) for 2 wk. In protocol 2, control and cirrhoti c rats received saline or IGF-I as a bolus injection of 1 mu g/100 g body w t followed by continuous infusion of the same dose for 100 min. In vivo D-g alactose absorption was reduced in cirrhotic rats compared with healthy con trols. IGF-I, as both a chronic (protocol I) and acute treatment (protocol 2), was able to improve sugar transport in cirrhotic rats but had no effect on sugar absorption in healthy rats. A significant elongation of enterocyt e microvilli was observed in cirrhotic animals; this alteration was totally or partially corrected by chronic or acute IGF-I administration. Our resul ts show that in vivo jejunal sugar transport and microvilli structure are a ltered in liver cirrhosis and that IGF-I, among other effects, mag correct these changes by modulating cytoskeletal organization in enterocytes.