Fig. (1).

Schematic view concerning the insulin-like effect. Insulin triggers the blood glucose uptake into the cells (step 4) and marks the beginning of the cellular signaling cascade. The active form of PTP1B (steps 5 and 6) is a negative regulator to the physiological (normal) glucose uptake (steps 1 to 4). Pharmacological re-activation of the signal cascade (steps 7 to 10) is achieved by vanadate as a functional antagonist to agonistic phosphate groups. Adapted from [20]. IR = insulin receptor; pTyr = phosphorylated tyrosine residues of the cytosolic beta subunit of IR. Step 11 (insulin-like effect) resembles step 4 (effect by insulin).