ISSN:
1471-4159
Source:
Blackwell Publishing Journal Backfiles 1879-2005
Topics:
Medicine
Notes:
Abstract— Metabolic relationships between the four major brain gangliosides, GM1, GD1a, GDlb and GT1 were studied in vivo. Labelled acetate and glucosamine were injected intracerebrally into 6–12-day-old rats and the radioactivities of the cerebral gangliosides were analysed. Radioactivity from [3H]acetate was determined in sialic acid, sphingosine and stearic acid and from [1-14C]glucosamine in hexosamine and sialic acid. The gangliosides were labelled in proportion to their pool size. In 6 day-old rats the labelling was approx. 30 per cent lower in the sialidase-stable sialyl group than in the labile one. When the brain gangliosides were labelled in 12-day-old rats, however, the specific activities of sialidase-labile and stable sialyl groups were the same at 0.5 months after the injection of precursors and disappeared at the same rate. The results indicate that at the age of 6 days a small pool of monosialogangliosides exists, which is converted to di- and trisialogangliosides. The degradation of gangliosides was studied by following the radioactivities in sphingosine and stearic acid from 2 to 6 months after the injection of labelled acetate. The specific activities of sphingosine and stearic acid decreased simultaneously at the same rate in all the four major gangliosides. The specific activity of stearic acid was the same in total brain lipids as in gangliosides. The half-lives for the degradation of the gangliosides were age-dependent and estimated to 60 days in adult rats. They were much shorter in younger rats but no reliable figures could be determined.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1111/j.1471-4159.1972.tb01378.x
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