Hepatic and pancreatic glycosphingolipid phenotypes of the neurological different rat strains.

Among three commonly used strains of laboratory rats, Wistar rats perform more neurological tasks better then Lewis and Sprague-Dawley (SD) rats. Liver is the main site of insulin-like growth factor (IGF) production and pancreas is the exclusive site of insulin production. Insulin stimulates neuronal development and appropriate IGF-I input is critical in brain growth. Glycosphingolipids (GSLs) are important mediators of insulin secretion and action. Therefore, this study investigated GSL phenotypes of liver and pancreas with hypothesis that they are different in three rat strains. Total GSL fractions (neutral and gangliosides) were analysed by high performance thin-layer chromatography (HPTLC). Complex gangliosides were detected by HPTLC immunostaining using cholera toxin B subunit after neuraminidase pretreatment. Wistar rats had the highest liver weight/body weight ratio and SD rats had the highest pancreas weight/body weight ratio. Ganglioside GM3 was more expressed in the liver of Wistar compared to Lewis and SD rats. SD rats contained scarce quantities of GD1a and b-series gangliosides in the liver compared to Wistar and Lewis rats. Pancreatic b-series ganglioside content was also the lowest in SD rats. This study represents differences in the hepatic and pancreatic ganglioside phenotypes of three rat strains that could influence IGF and insulin secretion and action.