Higher Degree Of Insulin Resistance Research Articles

Hyperlipoproteinemia with albumin-lipid complex: a novel type of hyperlipoproteinemia associated with insulin-resistant diabetes mellitus.

We describe a new phenotype of hyperlipoproteinemia in two members of a family with a high degree of consanguinity. Both have a history of uncontrolled diabetes mellitus without ketoacidosis, and a family history of coronary artery disease at a relatively early age. A high degree of insulin resistance was found. The abnormal lipoprotein(s) has alpha-lipoprotein mobility on cellulose acetate electrophoresis and has a relative density of less than 1.006 as determined by ultracentrifugation of serum collected after a short fast. The fraction isolated by ultracentrifugation contains about half of the serum cholesterol and triglycerides and most of the phospholipids; the major protein component is albumin. Immunoelectrophoresis showed low concentrations of beta-lipoproteins in both sera, and two abnormal precipitin bands against monospecific antiserum to antilipoprotein A; a third member of the family showed only one abnormal precipitin band against the same antibody. We tentatively propose an abnormal gene(s) as the underlying mechanism. The insulin-resistant diabetes mellitus, probably inherited separately, may aggravate the hyperlipidemia.

THE REACTION OF RABBIT ANTI-BEEF INSULIN SERUM WITH HETEROLOGOUS AND HOMOLOGOUS INSULIN PREPARATIONS.

A method for assaying antibodies to insulin that is based on the protection of insulin-I-131 from degradation by a liver extract is described. Moderately potent antibodies to insulin were obtained in rabbits by the injection of crystalline beef insulin, and a high degree of insulin resistance was demonstrable in some of the animals. The immunized animals did not become diabetic. The biological activity of various insulin preparations was detected by their ability to lower the blood sugar of rabbits or through the stimulation of glucose uptake by the rat hemidiaphragm. Crystalline beef insulin and crude extracts of beef pancreas were effectively neutralized under the conditions of the tests whereas corresponding pork insulin preparations were incompletely neutralized in the rat hemidiaphragm assay. The insulin activity of sera from beef, pork, sheep and human sources was neutralized by the rabbit antisera. The insulin activity of rabbit pancreas extracts and rabbit sera exhibited significant individual differences in the extent of neutralization. These observations on rabbit insulin preparations support the concept of Moloney and Coval that insulin of a given animal species can exist either in a “native” form that is not readily neutralized by antiserum produced in the same species, or an “altered” form that can be neutralized.