t-Tubules, calcium regulation and abnormal heart rhythms

Role of cardiac T-tubules in Ca regulation and arrhythmogenesis

In this project, Professor Clive Orchard and colleagues at the University of Bristol will investigate the regulation of calcium ions and the production of abnormal heart rhythms, called arrhythmia. They aim to determine whether t-tubules, which are part of the cell membrane, help to regulate the fluxes of calcium ions in the cell and whether this changes in heart failure, in which t-tubule structure and function change. Heart cells, and thus the heart, contract as a result of an increase in the concentration of calcium ions inside cells. This increase in calcium ion concentration occurs as a result of activity at the t-tubules. As well as causing contraction, this increase of calcium ions also regulates how many calcium ions enter and leave the cell during each contraction, and thus helps regulate the strength of contraction. However when there are too many calcium ions in the cell it can cause abnormal heart rhythm. This work will help improve the understanding of how calcium ions are normally regulated, how irregular heart rhythms are produced in the cell and how this changes in heart failure; this is important because such changes may contribute to decreased performance of the failing heart, and may suggest new treatments for irregular heart rhythms and for preventing decreased performance of a failing heart.