For example, Lin et al. demonstrated that acute exposure (1-h), of rabbit atrial myocytes to leptin, a peptide hormone involved in regulation of food intake (Wildman et al., 2000) and elevated in obesity (Ravussin et al., 2014), increased peak INa density (Lin et al., 2013). This evidence concerns the gene LEP and obesity due to melanocortin 4 receptor deficiency.