Glucose-6-phosphate dehydrogenase activity and glycogen content during chick neuroretinal cell culture

Abstract EN

Chick embryo neuroretinal (NR) cells transdifferentiate extensively into lens when cultured for several weeks in low glucose (F) medium, but largely inhibited when high levels of supplementary glucose (FG) are present.

Glucose-6-phosphate dehydrogenase activity i~ higher in FG (28 mM glucose final) cultures as compared to F (6 mM glucose final) cultures.

Another parameter strongly affected by ambient glucose levels is the accumulation of glycogen.

Glycogen synthesis increases steadily in FG cultures, but decreases very slightly under F conditions.

Glycogen accumulation in FG cultures is largely confined to glial-like (Muller) cells, particularly those underlying clusters of neurons.

Thus, high glucose may act in concert with neuronal influences to stimulate or stabilize the normal differentiation of retinal glial cells, whose characteristic features in vivo include glycogen syn!hesis and storage.