Antagonism of Insulin by Albumin

Antibody-Suppressible and Nonsuppressible Insulin-Like Activities in Human Serum and Their Physiologic Significance. An Insulin Assay With Adipose Tissue of Increased Precision and Specificity*

“…In any event, the increase of serum ILA upon dilution is of a different order of magnitude with the diaphragm (18,19), and it has been shown that an insulin antagonist associated with plasma albumin is likely to be responsible for this effect (37). It would appear from the data in this report as well as from other studies (38) According to Antoniades (40) and Shaw and Shuey (41), "free" insulin is released from a "bound" form in serum by incubation with adipose tissue homogenates. If such a process also took place in the presence of intact adipose tissue, the insulin "freed" during incubation might become subject to antibody suppression, and a progressive fall of the concentration of nonsuppressible ILA would be expected.…”

Effect of Very Small Concentrations of Insulin on Forearm Metabolism. Persistence of Its Action on Potassium and Free Fatty Acids without Its Effect on Glucose*

“…Difference in insulin responsiveness does not appear to lie in the responding tissue, as has been suggested by reports that an inhibitor impedes the action of insulin on excised muscle but not on excised adipose tissue (13)(14)(15)(16). From measurements of forearm metabolism, the difference in sensitivity resides in the mechanism by which glucose is translocated, whether in muscle or in adipose tissue, compared to the mechanism by which K is translocated, whether in muscle or in adipose tissue.…”

The role of adipose cell size and adipose tissue insulin sensitivity in the carbohydrate intolerance of human obesity

“…However, these do not explain the observations of the present study. The synalbumin antagonist does not interfere with the action of insulin upon adipose tissue (32,33) and it has been postulated that adipose tissue dissociates inactive "complexed" insulin to active "free" insulin. Furthermore, in the present investigation, adipose tissue was isolated from the organism and its circulation.…”