RYR2 and obesity due to melanocortin 4 receptor deficiency: The present results show that a relatively short period of high fat diet in Psammomys obesus gerbils, wild rodents with a genetic predisposition to develop obesity, diabetes and metabolic syndrome, results in severe alterations of cardiac structure, myocardial activation of inflammatory and apoptotic processes, and altered expressions of Ca2+-cycling proteins, including decreased expressions of SERCA2 and Cacna1c, increased expression CaMK2D, but no changes in RYR, phospholamban and Slc8a1 expressions.