Individual unstimulated GH4C1 cells exhibited spontaneous dynamic fluctuations in cytosolic free Ca2+ concentration ([Ca2+]i). Either chelation of extracellular Ca2+ with EGTA or treatment with nifedipine inhibited spontaneous [Ca2+]i fluctuations, indicating that the [Ca2+]i profile was dependent on the entry of extracellular Ca2+ via voltage-operated Ca2+ channels (VOCC). Spontaneous [Ca2+]i ...

The role of vacuolar Ca2+ transport systems in regulating cellular Ca2+ was investigated by measuring the vacuolar Ca2+ transport rate, the free energy available to drive vacuolar Ca2+ transport, the ability of the vacuole to buffer lumenal Ca2+, and the vacuolar Ca2+ efflux rate. The magnitude of the Ca2+ gradient generated by the vacuolar H+ gradient best supports a 1 Ca2+:2 H+ coupling ratio...

AimsUpregulation of Ca2+/calmodulin-dependent protein kinase II (CaMKII) contributes to the pathogenesis cardiovascular disease, including hypertension. Transgenic rats expressing human angiotensinogen gene [TGR (hAGT)L1623] are a new novel humanized model hypertension that associates with declines in cardiac contractile function and β-adrenergic receptor (AR) reserve. The molecular mechanisms ...

objective(s): thyroid hormones play an essential role in fetal growth and maternal hypo-thyroidism which leads to cardiovascular deficiency in their offspring.  considering this, we intended to investigate the impact of gestational hypothyroidism on offspring vascular contractibility and possible underlying mechanisms. materials and methods: hypothyroidism was induced in female rats by administ...

Revealing the binding properties of calcium ion (Ca2+) and magnesium (Mg2+) to terrestrial chromophoric dissolved organic matter (CDOM) facilities understanding effect natural water components on photophysics matter. Steady-state time-resolved fluorescence spectrometry, dynamic light scattering were applied investigate quenching process CDOM by Ca2+ Mg2+. Due a remarkable decrease steady-state ...

Depressed contractility is a central feature of the failing human heart and has been attributed to altered [Ca2+]i. This study examined the respective roles of the L-type Ca2+ current (ICa), SR Ca2+ uptake, storage and release, Ca2+ transport via the Na+-Ca2+ exchanger (NCX), and Ca2+ buffering in the altered Ca2+ transients of failing human ventricular myocytes. Electrophysiological techniques...

Cardiac alternans are thought to be a precursor to life-threatening arrhythmias. Previous studies suggested that alterations in sarcoplasmic reticulum (SR) Ca2+ content are either causative or not associated with myocyte Ca2+ alternans. However, those studies used indirect measures of SR Ca2+. Here we used direct continuous measurement of intra-SR free [Ca2+] ([Ca2+]SR) (using Fluo5N) during fr...