GANGLIOSIDE CONTENT OF RAT-LIVER AFTER ADMINISTRATION OF ETHANOL AND PENTAZOCINE OR SUCROSE SUPPLEMENTED DIETS

In a previous paper, we determined the effect of either ethanol or pen tazocine administered separately on the ganglioside content of rat liv er. In the present paper we have investigated the effect of pentazocin e injection on the liver ganglioside contents of chronic alcoholic rat s. The effect of high carbohydrate ingestion was also studied. Thirty male Wistar rats were divided into three experimental groups that rece ived ethanol and pentazocine, a carbohydrate supplemented diet or a la boratory diet and water. Liver ganglioside contents were slightly incr eased in the ethanol plus pentazocine group as compared to the control and high carbohydrate diet groups. No differences were found between the two latter groups. The percentage distribution of individual gangl iosides (ganglioside pattern) was also modified. A decrease in ganglio sides belonging to the b-series (G(D3), G(D1b), G(T1b) and G(Q1b)) in parallel with an increase in that of the a-series (G(M2), G(M1) and G( D1a)) were found for both the ethanol plus pentazocine and the high-ca rbohydrate fed rats. The results suggest that ethanol or high carbohyd rate ingestion diminishes the activity of G(D3) synthase, a key enzyme in the metabolism of gangliosides, which determines the proportion of gangliosides, belonging to the a- and b-series.