UCP3 and hyperinsulinism: The goals of the present study were to (1) reexamine in several rodent genetic models the impact of hyperinsulinemia and type 2 diabetes on cardiac UCP3 content, (2) investigate in a newly established, genetically modified rat model the consequences of a partial UCP3 deficiency, mimicking that seen with hyperinsulinemia and insulin resistance, on functional recovery of the heart subjected to I/R; and (3) identify the potential molecular mechanisms at play in the observed phenotype.