Expression of Neuropeptide Y, Substance P, and their receptors in the right atrium of diabetic patients.

Abstract

To investigate the expression of neuropeptides and their receptors that play a role in cardiac homeostasis in the right atrium of nondiabetic and diabetic patients undergoing coronary artery bypass graft surgery. The cardioactive neuropeptides and their receptors investigated in this study were Neuropeptide Y (NPY), and its receptors, NPY Receptor1 (NPY1R), NPY Receptor2 (NPY2R), NPY Receptor5 (NPY5R) and Substance P (SP) and its receptor, Neurokinin1R (NK1R). The gene and protein expression of NPY, NPY1R, NPY2R, NPY5R, SP and NK1R from the atrial tissue of 10 nondiabetic and diabetic patients undergoing coronary artery bypass grafting (CABG) was assessed by Q-RTPCR, immunohistochemistry, Western blot, and ELISA. Gene expression of NPY2R, NPY5R, preproTachykinin A (SP gene), and NK1R and their respective protein expression were significantly reduced whereas that of NPY and NPY1R were unchanged in the right atrium of diabetic patients compared to nondiabetic patients. These results demonstrate that the expression of neuropeptides and their receptors in the diabetic heart is significantly impaired, and may be the link between neuropathy and cardiac complications. Further studies are warranted to delineate pathophysiologic mechanisms associated with dysregulation of the cardiac neuropeptide system and the relationship to cardiac complications in diabetes. © 2011 Wiley Periodicals, Inc.