Some experiments on factors that can change insulin sensitivity

Local hormones such as adenosine or prostaglandins can dramatically change the sensitivity of glucose transport in muscle to insulin. It is possible that these factors may play a role in changes in insulin sensitivity in vivo produced by such diverse conditions as treatment with furosemide, thyroid status or catecholamine status. In particular, there is evidence that chronic elevation of catecholamine or sympathetic stimulation improves insulin sensitivity. Evidence is also available to support the view that elevation of plasma catecholamine concentrations results in increased thermogenesis through activation of substrate cycling in a number of tissues. Consequently, insulin resistance and decreased thermogenesis may be explained by decreased levels of catecholamines and/or a decreased sensitivity of skeletal muscle and perhaps other tissues to catecholamines or a decreased activity of the sympathetic nervous system.