INS and Hyperglycemia: In the STZ-NA model, first introduced by Masiello et al., NA was injected 15 min before STZ injection to provide partial protection in β-cells; stable hyperglycemia, reduced pancreatic insulin content by 60 %, and insulin responsiveness to glucose are among the main advantages of this model; lack of insulin resistance is its main disadvantage (Masiello et al., 1998[83]).