U. Sundaram et al., Corticosteroids reverse the inhibition of Na-glucose cotransport in the chronically inflamed rabbit ileum, AM J P-GAST, 39(1), 1999, pp. G211-G218
Citations number
20
Categorie Soggetti
da verificare
Journal title
AMERICAN JOURNAL OF PHYSIOLOGY-GASTROINTESTINAL AND LIVER PHYSIOLOGY
In a rabbit model of chronic ileal inflammation, we previously demonstrated
inhibition of Na-glucose cotransport (SGLT-1). The mechanism of inhibition
was secondary to a decrease in the number of cotransporters and not solely
secondary to an inhibition of Na-K-ATPase or altered affinity for glucose.
In this study, we determined the effect of methylprednisolone (MP) on SGLT
-1 inhibition during chronic ileitis. Treatment with MP almost completely r
eversed the reduction in SGLT-1 in villus cells from the chronically inflam
ed ileum. MP also reversed the decrease in Na-K-ATPase activity in villus c
ells during chronic ileitis. However, MP treatment reversed the SGLT-1 inhi
bition in villus cell brush-border membrane vesicles from the inflamed ileu
m, which suggested an effect of MP at the level of the cotransporter itself
. Kinetic studies demonstrated that the reversal of SGLT-1 inhibition by MP
was secondary to an increase in the maximal velocity for glucose without a
change in the affinity. Analysis of immunoreactive protein levels of the c
otransporter demonstrated a restoration of the cotransporter numbers after
MP treatment in the chronically inflamed ileum. Thus MP treatment alleviate
s SGLT-1 inhibition in the chronically inflamed ileum by increasing the num
ber of cotransporters and not solely secondary to enhancing the activity of
Na-K-ATPase or by altering the affinity for glucose.