Voltage dependence of the Ca2+ transient in endocardial and epicardial myocytes from the left ventricle of Goto–Kakizaki type 2 diabetic rats

Lina Al Kury, Vadym Sydorenko, Manal M.A. Smail, Muhammad Anwar Qureshi, Anatoliy Shmygol, Murat Oz, Jaipaul Singh, Frank Christopher Howarth

Research output: Contribution to journalArticlepeer-review

3 Citations (Scopus)

Abstract

Diabetes mellitus is a major global health disorder and, currently, over 450 million people have diabetes with 90% suffering from type 2 diabetes. Left untreated, diabetes may lead to cardiovascular diseases which are a leading cause of death in diabetic patients. Calcium is the trigger and regulator of cardiac muscle contraction and derangement in cellular Ca2+ homeostasis, which can result in heart failure and sudden cardiac death. It is of paramount importance to investigate the regional involvement of Ca2+ in diabetes-induced cardiomyopathy. Therefore, the aim of this study was to investigate the voltage dependence of the Ca2+ transients in endocardial (ENDO) and epicardial (EPI) myocytes from the left ventricle of the Goto–Kakizaki (GK) rats, an experimental model of type 2 diabetes mellitus. Simultaneous measurement of L-type Ca2+ currents and Ca2+ transients was performed by whole-cell patch clamp techniques. GK rats displayed significantly increased heart weight, heart weight/body weight ratio, and non-fasting and fasting blood glucose compared to controls (CON). Although the voltage dependence of L-type Ca2+ current was unaltered, the voltage dependence of the Ca2+ transients was reduced to similar extents in EPI–GK and ENDO–GK compared to EPI–CON and ENDO–CON myocytes. TPK L-type Ca2+ current and Ca2+ transient were unaltered. THALF decay of L-type Ca2+ current was unaltered; however, THALF decay of the Ca2+ transient was shortened in ENDO and EPI myocytes from GK compared to CON rat hearts. In conclusion, the amplitude of L-type Ca2+ current was unaltered; however, the voltage dependence of the Ca2+ transient was reduced to similar extents in EPI and ENDO myocytes from GK rats compared to their respective controls, suggesting the possibility of dysfunctional sarcoplasmic reticulum Ca2+ transport in the GK diabetic rat hearts.

Original languageEnglish
Pages (from-to)25-33
Number of pages9
JournalMolecular and cellular biochemistry
Volume446
Issue number1-2
DOIs
Publication statusPublished - Sep 1 2018

Keywords

  • Ca transient
  • Diabetes
  • Endocardial myocytes
  • Epicardial myocytes
  • Goto–Kakizaki rat
  • L-type Ca current
  • Rat heart
  • Ventricle

ASJC Scopus subject areas

  • Molecular Biology
  • Clinical Biochemistry
  • Cell Biology

Fingerprint

Dive into the research topics of 'Voltage dependence of the Ca2+ transient in endocardial and epicardial myocytes from the left ventricle of Goto–Kakizaki type 2 diabetic rats'. Together they form a unique fingerprint.

Cite this