title: Preservation of CGRP in myocardium attenuates development of cardiac dysfunction in diabetic rats.
abstract: BACKGROUND
  Calcitonin gene-related peptide (CGRP) plays an important role in cardiovascular regulation, which was found reduced in serum of diabetic patients. To test the hypothesis that lack of CGRP in myocardium is associated with diabetic cardiac dysfunction, which may be improved by preservation of CGRP in diabetic rats.
  
  
  RESULTS
  Diabetes was induced in male Sprague-Dawley rats by streptozotocin (50mg/kg). Two groups of the diabetic rats, one fed with standard laboratory chew and another with the laboratory food plus hot pepper (containing 0.0174% of capsaicin), to stimulate production and release of CGRP. Cardiac functions were evaluated by measurements of intraventricular pressures after 8weeks of development of diabetes. Transient receptor potential vanilloid type 1 (TRPV1), CGRP, β1-adreneregic receptor and norepinephrine were analyzed. Significantly lower levels of TRPV1 and CGRP were detected in the thoracic dorsal root ganglia (DRG) and myocardium of the diabetic animals, along with significant decline in left ventricular systolic pressure (by 24%) and heart rate (by 25%) and increase of the end-diastolic pressure (by 83%) with obvious reduction of CGRP in the DRG, by 41%, the myocardium (by 30%) and the serum (by 20%). The cardiac performance, the TRPV1 and the CGRP in the diabetic animals fed with hot pepper were well preserved. No any significant change in β1-adreneregic receptor and norepinephrine was detected.
  
  
  CONCLUSIONS
  The findings may suggest a novel mechanism underlying diabetic cardiac dysfunctions via impairing TRPV1-CGRP pathway in myocardium. Preservation of the TRPV1-CGRP mechanism may prevent the development of cardiac dysfunction in diabetes.
authors.affiliation: Department of Anesthesiology, Shanxi Medical University, 56 Xinjian Nan Road, Taiyuan 030001, Shanxi, China.
authors.forename: Tao
authors.initials: T
authors.lastname: Sun
authors.affiliation: Department of Anesthesiology, Shanxi Medical University, 56 Xinjian Nan Road, Taiyuan 030001, Shanxi, China; Department of Anesthesiology, Second Hospital of Shanxi Medical University, 382 Wuyi Road, Taiyuan 030001, Shanxi, China; Key Laboratory of Cellular Physiology at Shanxi Medical University, National Education Commission, 56 Xinjian Nan Road, Taiyuan 030001, Shanxi, China. Electronic address: guozheng713@163.com.
authors.forename: Zheng
authors.initials: Z
authors.lastname: Guo
authors.affiliation: Department of Anesthesiology, Shanxi Medical University, 56 Xinjian Nan Road, Taiyuan 030001, Shanxi, China.
authors.forename: Chao-Jie
authors.initials: CJ
authors.lastname: Liu
authors.affiliation: Department of Anesthesiology, Shanxi Medical University, 56 Xinjian Nan Road, Taiyuan 030001, Shanxi, China.
authors.forename: Mu-Rong
authors.initials: MR
authors.lastname: Li
authors.affiliation: Department of Anesthesiology, Shanxi Medical University, 56 Xinjian Nan Road, Taiyuan 030001, Shanxi, China.
authors.forename: Tu-Ping
authors.initials: TP
authors.lastname: Li
authors.affiliation: Department of Anesthesiology, Shanxi Medical University, 56 Xinjian Nan Road, Taiyuan 030001, Shanxi, China.
authors.forename: Xin
authors.initials: X
authors.lastname: Wang
authors.affiliation: Department of Anesthesiology, Shanxi Medical University, 56 Xinjian Nan Road, Taiyuan 030001, Shanxi, China.
authors.forename: Da-Jiang
authors.initials: DJ
authors.lastname: Yuan
mesh_terms: D000818:Animals; D015740:Calcitonin Gene-Related Peptide / Q000378:metabolism*; D002211:Capsaicin / Q000378:metabolism; D003921:Diabetes Mellitus, Experimental / Q000378:metabolism / Q000503:physiopathology; D006321:Heart / Q000503:physiopathology; D006339:Heart Rate / Q000502:physiology; D008297:Male; D009206:Myocardium / Q000378:metabolism*; D009638:Norepinephrine / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D018342:Receptors, Adrenergic, beta-1 / Q000378:metabolism; D015398:Signal Transduction / Q000502:physiology; D050916:TRPV Cation Channels / Q000378:metabolism*; D016276:Ventricular Function / Q000502:physiology*
chemical_list: D018342:Receptors, Adrenergic, beta-1; D050916:TRPV Cation Channels; D015740:Calcitonin Gene-Related Peptide; D002211:Capsaicin; D009638:Norepinephrine
keywords: CGRP; Calcitonin gene-related peptide; Cardiac dysfunction; Diabetes; TRPV1