The monocyte as a model for the study of insulin receptors in man.

We have characterized the cellular composition of preparations isolated from peripheral blood by Ficoll-Isopaque gradient centrifugation. 125I-insulin binding to every cell type was measured. A highly significantly positive correlation between specific cell binding fraction and the monocyte concentration of the heterogeneous cell suspension was demonstrated.

Decreased binding of insulin to its receptor in patients with congenital generalized lipodystrophy.

Patients with congenital generalized lipodystrophy are extremely insulin resistant. To ascertain whether this resistance is due to an insulin receptor defect, we tested four young patients with congenital generalized lipodystrophy and seven healthy persons of comparable age for the binding of 125I insulin to mononuclear leukocytes isolated from peripheral blood. Mononuclear leukocytes from patients with congenital generalized lipodystrophy bound significantly less insulin than cells from normal subjects (P less than 0.

The insulin receptor in normal and obese persons.

Using [125I]insulin at 172 pmol/1 (1 ng/ml) the binding of insulin to mononuclear leucocytes isolated from peripheral blood was studied. Our present study comprised 21 healthy subjects (22-33 years old, 90-110% of ideal weight) and a comparable group of 22 obese subjects (20-37 years old, minimum 150% of ideal weight). A significant difference in insulin binding was found between the two groups, the mean specific insulin binding fraction in normals being 1.

A study of insulin receptors in human mononuclear leucocytes.

Insulin binding sites were demonstrated in human mononuclear leucocytes by use of a technique which includes isolation of mononuclear leucocytes from defibrinated blood and separation of cell bound and free [125I]insulin with silicone oil. The binding was time and temperature dependent. At 15 degrees C equilibrium was reached after 90 min and a plateau maintained for at least 50 min.