Age-related alteration of brain gangliosides in senescence-accelerated mouse (SAM)-P/8

The senescence-accelerated mouse (SAM)-P/8 was examined with respect to changes in the content and composition of brain gangliosides during aging from juvenile to senescence. The gangliosides were compared with those of control mice, senescence-accelerated resistant mouse (SAM)-R/1. The ganglioside contents in the whole brains of SAM-P/8 and -R/1 were at almost constant level from 0.5 to 6 months, but decreased thereafter until senescence to about 80% of the levels reached at the younger ages. Upon aging, the ganglioside compositions changed with an increase of GM1, and decreases of GD1a, GD1b and GT1b in both strains (GT1b greater than GD1a greater than GD1b). A minor component, GM3 was two to four fold higher in the molecular distributions of the whole brain gangliosides of SAM-P/8 than those of -R/1 at any age examined throughout the life span. The regional gangliosides in olfactory bulb, cerebral cortex, hippocampus, hypothalamus, cerebellum, corpora quadrigemina region, brain stem and medulla oblongata were compared between the two strains at the age of three months. The ganglioside contents in the brain stem and medulla oblongata were lower in SAM-P/8 than -R/1, but there was no significant difference between the two strains in the other regions. As a minor component, GM3 was found to occur in a higher concentration in SAM-P/8 than -R/1 in all brain regions examined, except in the olfactory bulb where GM3 was detected as a major component with no difference in the distribution level between the two strains.