title: Regional effects of streptozotocin-induced diabetes on shortening and calcium transport in epicardial and endocardial myocytes from rat left ventricle.
abstract: In the heart, the left ventricle pumps blood at higher pressure than the right ventricle. Within the left ventricle, the electromechanical properties of ventricular cardiac myocytes vary transmurally and this may be related to the gradients of stress and strain experienced in vivo across the ventricular wall. Diabetes is also associated with alterations in hemodynamic function. The aim of this study was to investigate shortening and Ca2+transport in epicardial (EPI) and endocardial (ENDO) left ventricular myocytes in the streptozotocin (STZ)-induced diabetic rat. Shortening, intracellular Ca2+and L-type Ca2+current (ICa,L) were measured by video detection, fura-2 microfluorimetry, and whole-cell patch clamp techniques, respectively. Time to peak (TPK) shortening was prolonged to similar extents in ENDO and EPI myocytes from STZ-treated rats compared to ENDO and EPI myocytes from controls. Time to half (THALF) relaxation of shortening was prolonged in ENDO myocytes from STZ-treated rats compared to ENDO controls. TPK Ca2+transient was prolonged in ENDO myocytes from STZ-treated rats compared to ENDO controls. THALF decay of the Ca2+transient was prolonged in ENDO myocytes from STZ-treated rats compared to ENDO controls. Sarcoplasmic reticulum (SR) fractional release of Ca2+was reduced in EPI myocytes from STZ-treated rats compared to EPI controls. ICa,Lactivation, inactivation, and recovery from inactivation were not significantly altered in EPI and ENDO myocytes from STZ-treated rats or controls. Regional differences in Ca2+transport may partly underlie differences in ventricular myocyte shortening across the wall of the healthy and the STZ-treated rat left ventricle.
authors.affiliation: Department of Physiology, College of Medicine & Health Sciences, UAE University, Al Ain, UAE.
authors.forename: Manal M A
authors.initials: MM
authors.lastname: Smail
authors.affiliation: Department of Physiology, College of Medicine & Health Sciences, UAE University, Al Ain, UAE.
authors.forename: Muhammad A
authors.initials: MA
authors.lastname: Qureshi
authors.affiliation: Department of Physiology, College of Medicine & Health Sciences, UAE University, Al Ain, UAE.
authors.forename: Anatoliy
authors.initials: A
authors.lastname: Shmygol
authors.affiliation: Department of Pharmacology, College of Medicine & Health Sciences, UAE University, Al Ain, UAE.
authors.forename: Murat
authors.initials: M
authors.lastname: Oz
authors.affiliation: School of Forensic & Applied Sciences, University of Central Lancashire, Preston, UK.
authors.forename: Jaipaul
authors.initials: J
authors.lastname: Singh
authors.affiliation: Department of Cellular Membranology, Bogomoletz Institute of Physiology, Kiev, Ukraine.
authors.forename: Vadym
authors.initials: V
authors.lastname: Sydorenko
authors.affiliation: College of Natural & Health Sciences, Zayed University, Abu Dhabi, UAE.
authors.forename: Alya
authors.initials: A
authors.lastname: Arabi
authors.affiliation: Department of Physiology, College of Medicine & Health Sciences, UAE University, Al Ain, UAE chris.howarth@uaeu.ac.ae.
authors.forename: Frank C
authors.initials: FC
authors.lastname: Howarth
authors.affiliation: College of Natural & Health Sciences, Zayed University, Abu Dhabi, UAE.
authors.forename: Lina
authors.initials: L
authors.lastname: Al Kury
mesh_terms: D000818:Animals; D000903:Antibiotics, Antineoplastic / Q000008:administration & dosage / Q000009:adverse effects* / Q000627:therapeutic use; D002118:Calcium / Q000378:metabolism*; D020746:Calcium Channels, L-Type / Q000187:drug effects* / Q000378:metabolism; D003921:Diabetes Mellitus, Experimental / Q000139:chemically induced / Q000378:metabolism*; D006352:Heart Ventricles / Q000503:physiopathology; D017136:Ion Transport / Q000187:drug effects*; D008297:Male; D009200:Myocardial Contraction / Q000502:physiology; D032383:Myocytes, Cardiac / Q000187:drug effects* / Q000378:metabolism / Q000473:pathology; D018408:Patch-Clamp Techniques / Q000379:methods; D051381:Rats; D017208:Rats, Wistar; D012519:Sarcoplasmic Reticulum / Q000187:drug effects / Q000378:metabolism; D013311:Streptozocin / Q000008:administration & dosage / Q000009:adverse effects* / Q000627:therapeutic use; D059506:Telomere Shortening / Q000187:drug effects* / Q000235:genetics
chemical_list: D000903:Antibiotics, Antineoplastic; D020746:Calcium Channels, L-Type; D013311:Streptozocin; D002118:Calcium
keywords: Calcium transport; diabetes; endocardial myocytes; epicardial myocytes; rat heart; shortening; streptozotocin; ventricle