To investigate whether non-diabetic plasma affects insulin resistance in diabetes, Leprdb/db mice were subjected to Lepr+/+ plasma injection, and Lepr+/+, Leprdb/db, and Lepr+/+ plasma-injected Leprdb/db mice were administered with or without insulin to determine the level of Akt phosphorylation in the liver. Here, INS is linked to diabetes mellitus.