IN-VIVO MICRORADIOAUTOGRAPHIC STUDY OF INSULIN BINDING IN THE SKIN OFNORMAL 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 investigate d by in vivo microradioautography at 3 and 15 min. after intravenous i njection of I-125-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 interfo llicular epidermis, infundibulum, outer root sheath and blood vessels in the NIDDM mice, the bindings were much less than those of the contr ol mice at both 3 and 15 min. after I-125-insulin injection with an ex ception of the blood vessels at 3 min. The possible relationships betw een NIDDM and acanthosis nigricans from the viewpoint of insulin bindi ng are considered.