cytellin and Malabsorption-Syndromes

Small bowel transplantation impairs enteric function and causes malabsorption of cholesterol and bile acids. Growth hormone stimulates intestinal absorptive function. The authors hypothesized that long-term growth hormone therapy could improve absorption of bile acids and cholesterol after autotransplantation of the jejunoileum.. Sixteen pigs with similar food, cholesterol, and fat intake underwent either sham laparotomy or a model of jejunoileal autotransplantation, including extrinsic autonomic denervation, lymphatic interruption, and in situ cold ischemia. Five randomly chosen autotransplanted animals received daily growth hormone treatment for 8 weeks. Serum lipids, absorption, and excretion of cholesterol, bile acids, and fat were determined after 8 weeks. Mucosal morphometrics, proliferation, and enzyme activities were determined. Plasma cholesterol precursors and plant sterols, respective markers of cholesterol synthesis and absorption, were measured after 2 and 8 weeks.. After jejunoileal autotransplantation, growth hormone treatment significantly increased body weight gain, cholesterol absorption efficiency from 45.1% to 62.1%, plasma campesterol to cholesterol proportions, and biliary secretion of cholesterol. With or without growth hormone treatment, autotransplantation significantly increased fecal bile acid excretion, plasma cholesterol precursors, fecal bacterially modified neutral sterols, mucosal thickness of the ileum (but not jejunum), and intestinal transit time when compared with sham-operated animals. Crypt cell proliferation, mucosal enzyme activities, and microvilli showed no differences between the groups.. These findings suggest that growth hormone treatment selectively improves cholesterol, but not bile acid absorption, after autotransplantation of the jejunoileum.

Topics: Animals; Autonomic Denervation; Bile Acids and Salts; Cholesterol; Cholesterol, Dietary; Drug Evaluation, Preclinical; Feces; Female; Human Growth Hormone; Ileum; Intestinal Absorption; Intestinal Mucosa; Jejunum; Laparotomy; Lipids; Malabsorption Syndromes; Phytosterols; Postoperative Complications; Recombinant Proteins; Sitosterols; Sus scrofa; Transplantation, Autologous

The role of cholesterol and bile acid malabsorption in the regulation of plasma plant sterol levels was studied in 30 patients with an ileal resection (seven without any malabsorption, eight with bile acid malabsorption alone and 15 with bile acid, fat and cholesterol malabsorption) and nine with jejunoileal bypass (modest bile acid, and severe cholesterol and fat malabsorption). In contrast to cholesterol, plant sterols are not synthesized by the body, and so the plasma levels are regulated by their intestinal absorption and biliary secretion. In fact, the plant sterol, especially campesterol, levels were low in patients with cholesterol and fat malabsorption. Cholesterol absorption efficiency was a significant determinant of the plant sterol levels, suggesting that it reflects overall sterol absorption efficiency and that the plasma plant sterol levels, in turn, reflect cholesterol absorption. Bile acid malabsorption, though it appeared to promote biliary plant sterol secretion, had little direct effect on the plasma plant sterol contents. The results indicate that plasma campesterol levels can be used to evaluate cholesterol absorption efficiency in general and may reveal clinically significant steatorrhoea in patients with gut exclusion.

Topics: Adult; Aged; Cholesterol; Humans; Ileum; Intestinal Absorption; Jejunoileal Bypass; Lipids; Malabsorption Syndromes; Middle Aged; Phytosterols; Sitosterols