Modulation of Insulin Sensitivity of Hepatocytes by the Pharmacological Downregulation of Phospholipase D.

Background. The role of phospholipase D (PLD) as a positive modulator of glucose uptake activation by insulin in muscle and adipose cells has been demonstrated. The role of PLD in the regulation of glucose metabolism by insulin in the primary hepatocytes has been determined in this study.

Vitamin E prevents the age-dependent and palmitate-induced disturbances of sphingolipid turnover in liver cells.

Sphingolipid turnover has been shown to be activated at old age and in response to various stress stimuli including oxidative stress. Reduction of vitamin E content in the liver under the pro-oxidant action is associated with enhanced sphingolipid turnover and ceramide accumulation in hepatocytes. In the present paper, the correction of sphingolipid metabolism in the liver cells of old rats and in the palmitate-treated young hepatocytes using α-tocopherol has been investigated.