Prostaglandin biosynthesis and metabolism in rat brain slices.

Prostaglandin F2alpha and E were measured in the slices and in the media after incubation of rat brain slices. About 5 to 10 times more prostaglandin F2alpha than prostaglandin E was found, most of which was secreted into the media. In the absence of oxygen or in the presence of indomethacin, prostaglandin levels in both the slices and media were reduced. Serotonin, norepinephrine, epinephrine, and DOPA, at 10(-3) M concentrations, increased the prostaglandin F2alpha/E ratio in both the media and slices. The levels of prostaglandins F2alpha found in the slices and media when the slices were incubated with prostaglandin E2 increased significantly, this increase being independent of the presence of indomethacin. This suggests that prostaglandin E2 was being converted to F2alpha by a prostaglandin E2 9-ketoreductase in the rat brain slices.