Effect of insulin-like growth factor I on in vivo intestinal absorption of D-galactose in cirrhotic rats
Castilla-Cortázar I, Picardi A, Tosar A, Ainzúa J, Urdaneta E, García M, Pascual M, Quiroga J, Prieto J.
Department of Human Physiology, Liver Unit, School of Medicine, University of Navarra, 31080 Pamplona, Spain.
Insulin-like growth factor I (IGF-I) bioavailability is reduced in liver cirrhosis, a condition frequently associated with malnutrition. We have analyzed in vivo absorption of D-galactose by jejunal loops in rats with CCl4-induced liver cirrhosis and the influence of IGF-I on intestinal sugar transport in this disease.
Two different study protocols were followed. In protocol 1, healthy control rats or cirrhotic rats received saline or IGF-I (2 micrograms . 100 g body wt-1. day-1) for 2 wk. In protocol 2, control and cirrhotic rats received saline or IGF-I as a bolus injection of 1 microgram/100 g body wt followed by continuous infusion of the same dose for 100 min. In vivo D-galactose absorption was reduced in cirrhotic rats compared with healthy controls. IGF-I, as both a chronic (protocol 1) 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 enterocyte microvilli was observed in cirrhotic animals; this alteration was totally or partially corrected by chronic or acute IGF-I administration.
Our results show that in vivo jejunal sugar transport and microvilli structure are altered in liver cirrhosis and that IGF-I, among other effects, may correct these changes by modulating cytoskeletal organization in enterocytes.
CITATION Am J Physiol. 1999 Jan;276(1 Pt 1):G37-42