Effect of GM1-ganglioside on gastric mucosal epidermal growth factor and platelet-derived growth factor receptor...

The effect of intragastric administration of GM1-ganglioside on the expression of gastric mucosal epidermal growth factor (EGF) and platelet derived growth factor (PDGF) receptors was investigated. Gastric mucosal cell membranes were isolated from the stomach of groups of rats, one receiving twice daily for 3 consecutive days a dose of 0.25 mg/100g GM1-ganglioside, and the other only vehicle. Binding assays revealed the presence of both types of receptors, activation of which led to the elevation of tyrosine kinase activity as evidenced by a marked increase in membrane protein tyrosine phosphorylation patterns. The specific receptor binding in the control group was 2.47 fmol/mg protein for EGF and 1.46 fmol/mg protein for PDGF, whereas the respective binding values in the GM1-ganglioside treated group increased by 45% and 38%. The results suggest that GM1-ganglioside is capable of enhancement of gastric mucosal EGF and PDGF receptor activities.