Ca efflux via the sarcolemmal Ca ATPase occurs only in the t-tubules of rat ventricular myocytes

► In rat cardiac ventricular myocytes, Ca extrusion via the sarcolemmal Ca ATPase is localised to the t-tubules. ► Ca extrusion via sarcolemmal Ca ATPase is not regulated by PKA. ► Tonic PKA-induced stimulation of Ca extrusion via NCX occurs at the t-tubules but not the surface membrane.