Antagonism to Insulin Action on the Perfused Hind Limb of the Rat by a Reduced Insulin B Chain-Albumin Complex

A muscle perfusion technic, employing the hind limb of the rat, has been developed. Significant enhancement of glucose utilization by this tissue is seen with 500 μU./ml. of insulin. Maximal glucose uptake is seen at an insulin concentration of 1,000 μU./ml., although a significantly earlier insulin effect is noted when 10,000 μU./ml. is used.

The presence of 7.5 μg./ml. of a reduced B chain-albumin complex in the perfusion system causes highly significant inhibition of action of 1,000 μU./ml. of insulin. Neither equivalent concentrations of sulfonated B chain nor equimolar concentrations of a sulfhydryl donor, 2-mercaptoethanol, are capable of causing comparable insulin antagonism.