Transient increase in 3H-fucose incorporation following first exposure of dark-reared rats to light

Abstract

Incorporation of 3H-fucose into soluble and particulate glycoproteins of the visual and motor cortices of dark-maintained, light-exposed and normal rats was compared. Exposure to light for 1h had no effect but exposure for 3h led to a 23% elevation of incorporation into the particulate fraction of the visual cortex of light-exposed as compared to dark-maintained controls. However a 24h light exposure led to a depression in incorporation in this fraction from light-exposed rats to 83% that of the dark-maintained animals. These results demonstrate that a transient increase in synthesis of particulate glycoproteins occurs following first exposure to light followed by an increase in degradative processess leading to their breakdown.