Changes in membrane fatty acids and delta-9 desaturase in senescence accelerated (SAMP8) mouse hippocampus with aging.

Senescence accelerated mice (SAMP8) exhibit age induced impairments such as loss of memory and learning disabilities by the age of 8-10 months. Analysis of hippocampus of SAMP8 mice revealed that delta 9-desaturase (delta9desaturase) activity reduced up to 44-50% with age. Correspondingly, levels of unsaturated fatty acids are also lowered in the aged animals approximately to the same levels.

Rapid assay for nitric oxide synthase using thin-layer chromatography.

A simple, sensitive, and rapid method to determine the nitric oxide synthase (NOS) activity in crude cell extracts has been developed. The method takes advantage of differential migration of arginine and citrulline on silica gel thin-layer chromatography (TLC) with the specified buffer system. We have shown that products obtained by treating [14C]arginine with crude mouse hippocampal homogenate can be separated by methanol precipitation followed by TLC.