[Effect of fasting and refeeding on the adaptation of the small intestine in rats. A model for physiopathologic studies]. / Effet du jeûne et de la réalimentation sur l'adaptation de l'intestin grêle chez le rat. Un modèle d'études physio-pathologiques.

ABSTRACT

A chronological study was carried out on 50 male Wistar rats (350 g) to determine the effects of 3 days of fasting and 16 h to 9 days of refeeding on the morphology of jejunal and ileal mucosa (villus, crypt and enterocyte heights; number of mitosis), on some aspects of their functional adaptation (sucrase, maltase, protein) and on nitrogen and lipid absorptions. Three days of fasting resulted in weight loss (12 p. 100), in a jejunal mucosa atrophy (villus height 376 +/- 18 vs. 492 +/- 4 microns in controls; enterocyte height 31 +/- 2 vs. 41 +/- 0.3 micron in controls) and a decrease in disaccharidases activities (sucrase 927 +/- 90 vs. 3,363 +/- 21 mU/10 cm length in controls). No change in ileal mucosa morphometry was noticed. Ad libitum refeeding caused a rapid and progressive weight gain, a jejunal morphometric regrowth identical to control values at 16 h (villus height 521 +/- 20, enterocyte height 42 +/- 0.9 microns), and maximum at 40 h of refeeding (villus height 601 +/- 5 microns). Disaccharidases adaptation was delayed, with a maximum at 64 h of refeeding (sucrase 3,524 +/- 56 mU/10 cm length). Despite a 30 p. 100 increase of food consumption over the whole study (45 p. 100 during the first 16 h of refeeding), nitrogen and lipid absorption coefficients remained identical to those found in controls with an increased nitrogen balance of 70 p. 100 at 16 h and 54 p. 100 at 40 h refeeding, as compared to controls.(ABSTRACT TRUNCATED AT 250 WORDS)