Effects of prostaglandins E, precursors and some inhibitors of prostaglandin biosynthesis on dark- and light-induced leaflet movements in Cassia fasciculata Michx.

Prostaglandin E1 and prostaglandin E2 speed up the dark-induced (scotonastic) and light-induced (photonastic) leaflet movements of Cassia fasciculata. The precursors of prostaglandin biosynthesis, homo γ-linolenic and arachidonic acids, and an intermediary product, prostaglandin-interm-5, act in the same manner on these movements. Inhibitors of prostaglandin biosynthesis, indomethacin and phenylbutazone, inhibited the scotonastic but promoted the photonastic movements in an unexpected way. Since the pulvinar movements are mediated by water and ion migrations, the observed modifications of these movements indicate that prostaglandins and their precursors may affect, as in animal cells, processes linked to a variation of membrane permeability.