Insulin-like stimulation of glucose transport in isolated adipocytes by fatty acids

Abstract Glucose transport rate as assessed with the 3-O-Methyl-glucose method was significantly increased in adipocytes preincubated with aliphatic carboxylic acids. The magnitude of stimulation apparently depended on the chain length of the carboxylic acid, and was highest with palmitic acid (130 %). The stimulation was additive to the effect of insulin, and reflected a decrease of k m rather than an increase in v max of the transport rate. The results suggest that fatty acids may modulate the activity of the glucose transporter, providing an insulin-dependent supply of adipose tissue with glycerolphosphate during lipolysis for reesterification of excess fatty acids. Further, it is suggested that fatty acids mediate the stimulatory effect of catecholamines on glucose transport as observed in isolated fat cells.