AMPD3 and type 2 diabetes mellitus: The present study revealed previously unrecognized extramitochondrial localization of branched‐chain α‐keto acid dehydrogenase (BCKDH) and its reciprocal regulation with AMPD3 in cardiomyocytes and imbalanced AMPD3‐BCKDH interactions in a rat model of type 2 diabetes, Otsuka Long‐Evans‐Tokushima fatty (OLETF).