INS and Hyperglycemia: The STZ-NA hyperglycemic model developed by Masiello et al. (1998), which consists of generating a “type-2-diabetogenic” syndrome with the ability to respond to glucose-stimulated insulin secretion, is characterized by stable hyperglycemia due to the partial protection of nicotinamide (NA) against the specific β-cytotoxic effect of streptozotocin (STZ).