Premium
Streptozotocin‐induced diabetes modulates action potentials and ion channel currents from the rat atrioventricular node
Author(s) -
Yuill Kathryn H.,
Tosh David,
Hancox Jules C.
Publication year - 2010
Publication title -
experimental physiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.925
H-Index - 101
eISSN - 1469-445X
pISSN - 0958-0670
DOI - 10.1113/expphysiol.2009.050286
Subject(s) - streptozotocin , ion channel , atrioventricular node , diabetes mellitus , medicine , cardiology , action (physics) , endocrinology , cardiac action potential , chemistry , biophysics , electrophysiology , physics , biology , repolarization , receptor , tachycardia , quantum mechanics
The present study was conducted to evaluate whether experimentally induced type 1 diabetes results in alterations to atrioventricular nodal (AVN) electrophysiology at the cellular level. Spontaneous action potentials (APs) and ionic currents were recorded from AVN myocytes isolated from the hearts of control rats and from those with streptozotocin‐induced diabetes. Perforated patch‐clamp recordings were used to assess changes in cellular AP parameters and in ionic currents. Type 1 diabetes significantly increased AP duration, whilst reducing AP firing rate, upstroke velocity and rate of diastolic depolarization. The diabetes‐induced changes in AP parameters were accompanied by a significant leftward shift in the zero current potential under voltage clamp, a reduction in peak L‐type Ca 2+ current density and reduced amplitude of delayed rectifier and hyperpolarization‐activated currents. These findings demonstrate that experimentally induced type 1 diabetes can lead to remodelling of AVN cellular electrophysiology.