Effect of Streptozotocin-Induced Type 1 Diabetes Mellitus on Contraction, Calcium Transient, and Cation Contents in the Isolated Rat Heart

  1. JAIPAUL SINGH1,
  2. APURVA CHONKAR1,
  3. NICHOLAS BRACKEN1,
  4. ERNEST ADEGHATE2,
  5. ZAY LATT1,
  6. MUNIR HUSSAIN3

Article first published online: 28 NOV 2006

DOI: 10.1196/annals.1372.028

Issue

Annals of the New York Academy of Sciences

Additional Information

How to Cite

SINGH, J., CHONKAR, A., BRACKEN, N., ADEGHATE, E., LATT, Z. and HUSSAIN, M. (2006), Effect of Streptozotocin-Induced Type 1 Diabetes Mellitus on Contraction, Calcium Transient, and Cation Contents in the Isolated Rat Heart. Annals of the New York Academy of Sciences, 1084: 178–190. doi: 10.1196/annals.1372.028

Author Information

  1. 1

    Department of Biological Sciences, University of Central Lancashire, Preston, Lancashire, PR1 2HE United Kingdom

  2. 2

    Department of Anatomy, Faculty of Medicine & Health Sciences, United Arab Emirates University, Al Ain, UAE

  3. 3

    Department of Medicine, University of Liverpool, Daulby Street, Liverpool, L69 7ZX United Kingdom

*Address for corresspondence: Prof. Jaipaul Singh, Department of Biological and Forensic Sciences, University of Central Lancashire, Preston, Lancashire, PR1 2HE UK. Voice: 00-44-1772-893515; fax: 00-44-1772-892929.  e-mail: jsingh3@uclan.ac.uk

Publication History

  1. Issue published online: 28 NOV 2006
  2. Article first published online: 28 NOV 2006

SEARCH

SEARCH BY CITATION

ARTICLE TOOLS

View Full Article (HTML) Get PDF (301K)

Keywords:

  • heart;
  • diabetes mellitus;
  • rat;
  • cations;
  • contraction;
  • calcium

Abstract: Cations play major physiological and biochemical roles in the excitation–contraction coupling processes in the heart. This study investigated the effect of streptozotocin (STZ)-induced type I diabetes mellitus (DM) on contraction, calcium transient [Ca2+]i, and cation contents in the isolated rat heart compared to age-matched control. Diabetes rats weighed significantly (P < 0.05) less compared to control. They also had significantly (P < 0.05) elevated blood glucose compared to control. The whole heart, as well as the atria, right and left ventricles of the diabetic heart weighed significantly (P < 0.05) less compared to hearts from age control rats. The force of contraction and time to peak (t-pk) contraction in diabetic ventricular myocytes increased significantly (P < 0.05) compared to control. By contrast, these parameters did not change for the Ca2+ transient except for the time to half (t½) relaxation. The levels of sodium (Na+), potassium (K+), calcium (Ca2+), magnesium (Mg2+), iron (Fe2+), copper (Cu2+), and zinc (Zn2+) in the hearts varied from diabetic compared to control animals. The results indicate that 6–8 weeks of STZ-induced DM is associated with marked changes in contraction and in cation contents of the heart. The delay in the t½ relaxation of the Ca2+ transient may be responsible for the elevated contraction seen in the diabetic heart. Moreover, the changes in cation contents in the heart may be responsible for abnormal cardiac rhythms and activity during DM.

View Full Article (HTML) Get PDF (301K)