INCREASED PLASMA, BILIARY, AND HEPATIC CHOLESTEROL PRECURSORS IN PIGSWITH ILEAL AUTOTRANSPLANTATION-INDUCED MALABSORPTION OF CHOLESTEROL AND BILE-ACIDS
Mp. Pakarinen et al., INCREASED PLASMA, BILIARY, AND HEPATIC CHOLESTEROL PRECURSORS IN PIGSWITH ILEAL AUTOTRANSPLANTATION-INDUCED MALABSORPTION OF CHOLESTEROL AND BILE-ACIDS, Scandinavian journal of gastroenterology, 33(3), 1998, pp. 319-326
Background: Small-bowel transplantation impairs intestinal absorptive
function for unknown reasons. Methods: The proportions of plasma, bili
ary, and hepatic cholesterol precursors to cholesterol were determined
by gas-liquid chromatography after resection of the proximal 75% of t
he porcine jejunoileum (n = 15) and autotransplantation of the remaini
ng ileum (n = 15) and were related to in vivo absorption and fecal exc
retion of cholesterol. Results: Ileal autotransplantation significantl
y decreased serum (18%; P < 0.05) and liver (7.6%; P < 0.05) cholester
ol content, the esterification percentage of serum cholesterol (5.1%;
P < 0.0001), and the total amount of cholesterol absorbed (48%; P < 0.
05) and increased fecal excretion of bile acids (108%; P < 0.0001), ne
t cholesterol elimination (53%; P < 0.001), and the proportions of pla
sma (207%; P < 0.0001), biliary (183%; P < 0.0001), and hepatic (114%;
P < 0.0001) cholesterol precursors. The increases were most striking
for the side-chain-saturated demethylated sterols, cholestenol and lat
hosterol, and monomethyl sterols, whose bile/liver and plasma/liver ra
tios were increased in the autotransplantation group. Plasma, biliary,
and hepatic precursor proportions were positively related to each oth
er and similarly correlated with fecal bile acids and the net eliminat
ion of cholesterol in feces. Conclusions: These findings suggest that
ileal autotransplantation in pigs with proximal gut resection increase
d the levels of cholesterol precursor sterols in plasma, bile, and liv
er mainly due to a bile-acid-malabsorption-induced increase in hepatic
synthesis of cholesterol. Enhanced secretion of cholesterol precursor
s from the liver into the plasma and bile may have contributed to thei
r increased values during the increased rate of cholesterogenesis.