Factors regulating prostaglandin uptake by rat small intestine

The uptake of prostaglandin E1 by rat intestine mucosal strips was investigated. The results indicate that: (1) PGE1 did not accumulate in the epithelial cells of rat intestine. The intracellular to extracellular distribution ratio did not reach unity in spite of the extended periods of incubation. (2) A decrease in the sodium gradient across the brush-border membrane of intestinal cells significantly inhibited PGE1 uptake by the mucosal strips. (3) PGE1 uptake increases with increasing concentration of potassium in the incubation medium with a tendency for saturation at high K+ levels. (4) Calcium and magnesium ions had no effect on the steady-state uptake of PGE1 by the epithelial cells of rat intestine. (5) Addition of sodium carbonate or phosphate to the incubation medium significantly decreased PGE1 uptake by the intestinal cells. (6) Further studies of PGE1 uptake reveal a temperature-dependent process with a Q10 of 2.8.