Insertion of functional intact insulin receptors into hepatocytes.

Isolated insulin receptors were inserted into hepatocytes by fusion with receptor-lysophospholipid micelles. The number of receptors was increased approximately two times as monitored by insulin binding experiments. Addition of exogenous receptors resulted in increased receptor autophosphorylation. The exogenous added receptors could be coupled to the intracellular effector system as shown by increased phosphorylation of the insulin receptor substrate 1, IRS-1, and by increased glycogen synthesis. The co-incorporated lysophospholipid was partly metabolized to phospholipid. This method for introducing insulin receptors into cells represents a novel system to study the pathway of insulin signalling and may provide information as to the role of variation of receptor number in insulin action in cellular metabolism of specific cells.