M. Pakarinen et al., ADAPTATION OF CHOLESTEROL ABSORPTION AFTER PROXIMAL RESECTION OF PORCINE SMALL-INTESTINE, Journal of lipid research, 37(8), 1996, pp. 1766-1775
Cholesterol absorption occurs primarily in the upper small intestine.
Our aim was to assess absorption of cholesterol during ileal adaptatio
n after proximal small intestinal resection. In vivo absorption and el
imination of cholesterol, plasma cholesterol, cholesterol precursors,
and plant sterols were related to intestinal morphology and transit 4
(n = 5), 8 (n = 5), and 14 (n = 5) weeks after a 75% proximal resectio
n of porcine small intestine, and compared to preoperative (n = 5) and
transected (n = 5) control animals. Fractional cholesterol absorption
, the daily amount of cholesterol absorbed, plasma cholesterol, and pl
ant sterol to cholesterol proportions were significantly (P < 0.05 or
less) decreased, whereas fecal loss of cholesterol as neutral steroids
, less so as bile acids, plasma cholesterol precursor proportions, and
ileal mass and villus height were significantly increased (P < 0.05 o
r less) after 8 weeks of the resection. Cholesterol absorption efficie
ncy, decreased by the resection, was gradually increased from 5.4 +/-
2.2 to 26.9 +/- 3.9% during the 14 postoperative weeks (P < 0.0001) si
multaneously with a 46% increase in villus height compared with transe
ction (P < 0.0001), but absorption remained still below control levels
(80.4 +/- 2.5%, P < 0.0001). In resected and control animals, villus
height correlated positively with cholesterol absorption efficiency (r
= 0.85, P < 0.0001; r = 0.76, P = 0.01) and plasma plant sterol propo
rtions (r = 0.94-0.95, P < 0.0001; r = 0.78-0.85, P < 0.008), respecti
vely. In conclusion, after massive proximal small bowel resection, ada
ptation of intestinal cholesterol absorption efficiency occurs in the
distal ileum closely paralleling villus hypertrophy.