SYNTHESIS OF GANGLIOSIDES DURING DEVELOPMENT AND ITS RELATION TO THE QUANTITATIVE CHANGES OF SUBCELLULAR PARTICLES OF RAT BRAIN

Abstract

Abstract— Different subcellular fractions prepared from developing rat cerebrum were quantified by determinations of dried weights and protein contents. It was found that there is an increase of 2–2·5 times in the weights of synaptosomes and mitochondria/g of tissue during the first 20 days of extrauterine life. A period of fast synthesis of gangliosides, with a similar pattern of increase for the different subcellular particles, was found during the first 15 days of life by study of the incorporation of injected d ‐[1‐ 14 C]glucosamine in rats at different stages of development. Attempts to find out if gangliosides from a certain fraction are precursors of those of other fractions indicated that in all fractions the gangliosides increase independently of the other fractions. It is concluded that the enzymic systems of synthesis of these glycolipids are present in vivo in all the fractions considered.