Background: Adipogenesis is affected by multiple factors, among which all-trans retinoic acid (ATRA) and Ca2+are considered important factors. Objectives: This study aimed to evaluate the effect of calcium, ATRA, their underlying molecular mechanisms, alone in combination, on adipocyte differentiation. Methods: Human adipose-derived mesenchymal stem cells (hAD-MSCs) were differentiated into adi...

Ultrafine particles have been shown to induce pro-inflammatory effects both in vivo and in vitro. Increased expression of pro-inflammatory genes probably requires the activation of specific transcription factors such as nuclear factor kappa B (NF-kappaB) via a number of possible pathways including Ca2+ and reactive oxygen species. The fluorescent dye fura 2, was used to measure cytosolic Ca2+ i...

In ventricular cardiac myocytes, T-tubule density is an important determinant of the synchrony of sarcoplasmic reticulum (SR) Ca2+ release and could be involved in the reduced SR Ca2+ release in ischemic cardiomyopathy. We therefore investigated T-tubule density and properties of SR Ca2+ release in pigs, 6 weeks after inducing severe stenosis of the circumflex coronary artery (91+/-3%, N=13) wi...

Although the accumulation of intracellular calcium ions ([Ca2+]i) is associated with muscle damage, little is known regarding the temporal profile of muscle [Ca2+]i under in vivo conditions, and, specifically, the effects of different contraction types [e.g., isometric (ISO); eccentric (ECC)] on [Ca2+]i remain to be determined. The following hypotheses were tested. 1) For 90 min at rest, an in ...

Schertzer, J. D., H. J. Green, and A. R. Tupling. Thermal instability of rat muscle sarcoplasmic reticulum Ca2 -ATPase function. Am J Physiol Endocrinol Metab 283: E722–E728, 2002; 10.1152/ajpendo.00204.2002.—To examine the thermal instability and the role of sulfhydryl (SH) oxidation on sarcoplasmic reticulum (SR) Ca2 -ATPase function, crude homogenates were prepared from the white portion of ...

Arterial hypertension is a common side effect of cyclosporine A therapy; however, the cellular mechanism of cyclosporine A-induced hypertension is still unknown. The present study, therefore, examined the effect of cyclosporine A on Ca2+ kinetics and contraction in primary cultures of vascular smooth muscle cells. Cyclosporine A (10 micrograms/ml) did not affect resting intracellular free Ca2+ ...

The purpose of this study was to investigate the effects of the intracellular messenger cyclic GMP (cGMP) on sequestration of cytosolic calcium (Ca2+) into the intracellular Ca2+ store (the sarcoplasmic reticulum) of vascular smooth muscle. Using saponin-skinned primary cultures of rat aortic smooth muscle, we investigated the effect of cGMP on 45Ca uptake in monolayers of cells. The intracellu...

BACKGROUND In the failing human heart, altered Ca2+ homeostasis causes contractile dysfunction. Because Ca2+ and Na+ homeostasis are intimately linked through the Na+/Ca2+ exchanger, we compared the regulation of [Na+]i in nonfailing (NF) and failing human myocardium. METHODS AND RESULTS [Na+]i was measured in SBFI-loaded muscle strips. At slow pacing rates (0.25 Hz, 37 degrees C), isometric ...

With the use of the patch-clamp technique, five kinds of stretch-activated (SA) ion channels were identified on the basis of their single-channel conductances and ion selectivities in cultured chick ventricular myocytes. Because a high-conductance K+-selective channel predominated among these channels, we concentrated on characterizing its properties mostly using excised inside-out patches. Wit...

BACKGROUND In heart failure, protein kinase A-mediated hyperphosphorylation of ryanodine receptors (RyRs) in sarcoplasmic reticulum (SR) causes dissociation of FKBP12.6 from RyRs. This results in an abnormal Ca2+ leak through RyRs, possibly leading to cardiac dysfunction. In the present study, we assess whether beta-blockers can correct this defect in RyR in tachycardia-induced heart failure an...