Na(+)-K(+)-Cl(-) cotransporter isoform 1 (NKCC1) and reverse mode operation of the Na(+)/Ca(2+) exchanger (NCX) contribute to intracellular Na(+) and Ca(2+) overload in astrocytes following oxygen-glucose deprivation (OGD) and reoxygenation (REOX). Here, we further investigated whether NKCC1 and NCX play a role in mitochondrial Ca(2+) (Ca(m)(2+)) overload and dysfunction. OGD/REOX caused a doub...

BACKGROUND AND PURPOSE The 3 gene products of the Na(+)/Ca(2+) exchanger (NCX), viz, NCX1, NCX2, and NCX3, may play a pivotal role in the pathophysiology of brain ischemia. The aim of this study was to investigate the transductional and posttranslational mechanisms involved in the expression of these isoforms during oxygen and glucose deprivation and their role in endoplasmic reticulum Ca(2+) r...

Na-Ca exchange (NCX) is crucial in the regulation of [Ca]i and cardiac contractility, but key details of its dynamic function during the heartbeat are not known. In the present study, we assess how NCX current (INCX) varies during a rabbit ventricular action potential (AP). First, we measured the steady-state voltage and [Ca]i dependence of INCX under conditions when [Ca ]i was heavily buffered...

Sodium/calcium (Na+/Ca2+) exchange (NCX) overexpression is common to human heart failure and heart failure in many animal models, but its specific contribution to the cellular Ca2+ ([Ca2+]i) handling deficit is unclear. Here, we investigate the effects of exchange inhibitory peptide (XIP) on Ca2+ handling in myocytes isolated from canine tachycardic pacing-induced failing hearts. Whole-cell pat...

The renal connecting tubule (CNT) is a distinct segment that occurs between the distal convoluted tubule (DCT) and the cortical collecting duct. On the basis of its characterization in rabbit it is widely believed that connecting tubule cells have a low permeability to water and do not respond to vasopressin. Here we utilize segment-specific markers and specific aquaporin antibodies to characte...

In mammalian cardiac ventricular myocytes, Ca efflux via Na/Ca exchange (NCX) occurs predominantly at T tubules. Heart failure is associated with disrupted t-tubular structure, but its effect on t-tubular function is less clear. We therefore investigated t-tubular NCX activity in ventricular myocytes isolated from rat hearts ∼18 wk after coronary artery ligation (CAL) or corresponding sham oper...

The electrogenic Na/Ca exchanger (NCX) mediates bidirectional Ca movements that are highly sensitive to changes of Na gradients in many cells. NCX1 is implicated in the pathogenesis of heart failure and a number of cardiac arrhythmias. We measured NCX1 palmitoylation using resin-assisted capture, the subcellular location of yellow fluorescent protein-NCX1 fusion proteins, and NCX1 currents usin...

BACKGROUND Chronic exercise and food restriction (FR) have directionally opposite changes in transcription of molecular structures of calcium handling and thyroid hormone (TH) status. OBJECTIVE Evaluate the association of chronic exercise and FR on serum thyroid hormones and gene transcription of molecular structures of intracellular calcium transients and thyroid receptors in myocardium of r...

Na -Ca exchange (NCX) is crucial in the regulation of [Ca ]i and cardiac contractility, but key details of its dynamic function during the heartbeat are not known. In the present study, we assess how NCX current (INCX) varies during a rabbit ventricular action potential (AP). First, we measured the steady-state voltage and [Ca ]i dependence of INCX under conditions when [Ca 2 ]i was heavily buf...

Gadeberg HC, Kong CH, Bryant SM, James AF, Orchard CH. Sarcolemmal distribution of ICa and INCX and Ca autoregulation in mouse ventricular myocytes. Am J Physiol Heart Circ Physiol 313: H190–H199, 2017. First published May 5, 2017; doi:10.1152/ ajpheart.00117.2017.—The balance of Ca influx and efflux regulates the Ca load of cardiac myocytes, a process known as autoregulation. Previous work has...