Dietary regulation of glucose transporter gene expression: tissue specific effects in adipose cells and muscle.

The rapid stimulation of glucose transport into the classic insulin responsive tissues, muscle and adipose cells, is crucial for maintenance of glucose homeostasis in the fed state. Macronutrient content and composition of the diet strongly influence glucose transport into these tissues by altering both the expression of the glucose transporter genes (GLUT1 and GLUT4) and the functional activity of the gene products. Dietary regulation of GLUT1 and GLUT4 is tissue specific. With high fat feeding alterations in transporter expression is much greater in adipose cells than in skeletal muscle. In the unfed state there is a profound down regulation of glucose transporter gene expression in adipose cells while expression of the same transporter genes is increased in skeletal muscle. Thus, tissue specific regulation of glucose transporter expression and function appears to be part of the adaptive response to maintain adequate cellular nutrition in times of altered nutrient availability.