TY - JOUR
T1 - Methylprednisolone accelerates the ontogeny of sodium-taurocholate cotransport in rat ileal brush border membranes
AU - Barnard, J. A.
AU - Ghishan, F. K.
PY - 1986/12
Y1 - 1986/12
N2 - The effect of methylprednisolone on the postnatal maturation of taurocholate transport was studied by using isolated ileal brush border membrane vesicles. Vesicles were prepared from 14-day-old control, 14-day-old methylprednisolone-treated, and untreated 21-day-old rats. Methylprednisolone treatment resulted in a significant stimulation of taurocholate uptake by an inwardly directed Na+ gradient when compared with a choline gradient incubation. These differences occurred at 20 seconds and 1, 2, and 5 minutes of incubation (P < 0.05). In 14-day-old controls, uptake was similar for Na+ and choline gradients. A plot of active uptake velocity vs. taurocholate concentration (0.1 to 1.0 mmol/L) in 14-day-old controls was linear and approached the abscissa, indicating the absence of active transport. Plots for methylprednisolone-treated rats showed saturability. An inwardly directed Na+ gradient stimulated initial taurocholate uptake rates by twofold at 37 ° C (P < 0.01), but not at 4 °C. Glycocholate and glycodeoxycholate inhibited Na+-stimulated taurocholate uptake by 50% (P < 0.01) and 20% (P < 0.05), respectively. These data indicate that pharmacologic doses of methylprednisolone accelerate the postnatal acquisition of Na+-dependent taurocholate cotransport in rat ileal brush border membranes.
AB - The effect of methylprednisolone on the postnatal maturation of taurocholate transport was studied by using isolated ileal brush border membrane vesicles. Vesicles were prepared from 14-day-old control, 14-day-old methylprednisolone-treated, and untreated 21-day-old rats. Methylprednisolone treatment resulted in a significant stimulation of taurocholate uptake by an inwardly directed Na+ gradient when compared with a choline gradient incubation. These differences occurred at 20 seconds and 1, 2, and 5 minutes of incubation (P < 0.05). In 14-day-old controls, uptake was similar for Na+ and choline gradients. A plot of active uptake velocity vs. taurocholate concentration (0.1 to 1.0 mmol/L) in 14-day-old controls was linear and approached the abscissa, indicating the absence of active transport. Plots for methylprednisolone-treated rats showed saturability. An inwardly directed Na+ gradient stimulated initial taurocholate uptake rates by twofold at 37 ° C (P < 0.01), but not at 4 °C. Glycocholate and glycodeoxycholate inhibited Na+-stimulated taurocholate uptake by 50% (P < 0.01) and 20% (P < 0.05), respectively. These data indicate that pharmacologic doses of methylprednisolone accelerate the postnatal acquisition of Na+-dependent taurocholate cotransport in rat ileal brush border membranes.
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M3 - Article
C2 - 3023509
AN - SCOPUS:0023010613
SN - 0022-2143
VL - 108
SP - 549
EP - 555
JO - The Journal of Laboratory and Clinical Medicine
JF - The Journal of Laboratory and Clinical Medicine
IS - 6
ER -