Dr. Munir Hussain,

Associate Professor

Research

Mechanisms regulating the heart beatCardiac electrophysiology The heart is one of the vital organs in the body that serves to pump blood to the metabolising tissues around the body. To perform this function adequately, the heart has to adapt to the changing needs of the body by altering the strength of contraction as well as the heart rate. Both these parameters are regulated by the transport of ions, particularly Na+, K+ and Ca2+, across the surface membrane of the single cells (cardiac myocytes) that make up the heart. My main research interests are focused on how the transport of these ions alters the electrical activity of the heart at the single cell level. The transport of ions across the membrane occurs through proteins that function as ion channels, exchangers and pumps. Each of these proteins is regulated in such a way so that the heart beat can be regulated to match the changing needs of the body on a beat-to-beat basis. In my laboratory we use the voltage (patch) clamp technique to study the physiology and pharmacology of ion channels at the cellular and molecular level.Excitation-contraction coupling Electrical activity of the heart is finely coupled to the contraction of the heart, which in turn depends mainly on the amount of calcium released from specialised intracellular compartments called the sarcoplasmic reticulum (SR). Mechanisms that control the release and re-uptake of Ca2+ from the SR are critical to initiating the heart beat as well as defining the duration of contraction and also the rate at which the heart relaxes. Another one of my main interests is to use fluorescence imaging simultaneously with voltage clamp to study the mechanisms that control the release and reuptake of Ca2+ from the intracellular compartments at the single cell level.