Polyphosphoinositide hydrolysis in response to light stimulation of rat and chick retina and retinal rod outer segments

Light-induced phosphoinositide degradation and light-induced structural alterations in the rat retina are enhanced after chronic lithium treatment

In the rat retina, light-induced break down of polyphosphoinositides and structural alterations of photoreceptor outer segment disk-membranes were enhanced by chronic lithium treatment at doses equivalent to therapeutic levels in humans. Furthermore, the recovery of phosphoinositide baseline levels after light exposure was delayed in lithium treated retinas. Light and lithium may thus affect phospholipid membranes in the retina. Initial processes in the pathogenesis of light damage in the retina are largely unknown to date. The hydrolysis of polyphosphoinositides may possibly constitute such an initial event.