In vivo microradioautographic study of insulin binding in the skin of normal and NIDDM mice: with special reference to acanthosis nigricans.

Insulin bindings in the tissues and cells in the skin of non-diabetic (control) and genetically diabetic db/db (NIDDM) mice were investigated by in vivo microradioautography at 3 and 15 min. after intravenous injection of 125I-insulin. Specific insulin bindings were observed in the interfollicular epidermis, infundibulum, dermis, outer root sheath, sebaceous glands and blood vessels, but not in the hair shaft of the control mice. Although the specific bindings were seen in the interfollicular epidermis, infundibulum, outer root sheath and blood vessels in the NIDDM mice, the bindings were much less than those of the control mice at both 3 and 15 min. after 125I-insulin injection with an exception of the blood vessels at 3 min. The possible relationships between NIDDM and acanthosis nigricans from the viewpoint of insulin binding are considered.