Protein kinase C and leucine metabolism in intestinal crypt cells.

Intestinal cells were separated into fractions rich in villous or crypt cells. Alkaline phosphatase, present in villous cells, but absent from crypt cells, was used as a marker. Crypt cells were 3-6 times as active as villous cells in the metabolism of leucine or mevalonate. The previously reported stimulatory effect of albumin was twice as strong in crypt cells as that in villous cells. Reduced glutathione, spermidine HCl and ethanolamine (0.5-10 mM) did not replace albumin, the effect of which was maximal at 0.02 mM. Protein kinase C was shown to be present mainly in crypt cells.