The proper intracellular Ca(2+) signaling is essential for normal cell functions and organ development, and the maintaining Ca(2+) homeostasis in cardiac myocytes is of functional importance for the intact heart. As the first functional organ in the vertebrate embryo, the heart is continuously remodeled and maintains its physiologic pumping function in response to increasing circulatory demands. The expressions of Ca(2+) handing proteins in the embryonic heart, however, are different from those in neonatal and adult hearts, which means that the regulation of Ca(2+) transients in embryonic cardiomyocytes is different from that in adult cardiac myocytes. Recent advances in molecular and cellular biology, as well as the application of embryonic stem cell differentiation system, have made progress in uncovering the regulation of Ca(2+) homeostasis during cardiomyogenesis. This paper briefly summarizes the Ca(2+) homeostasis during early development of cardiomyocytes and reviews current knowledge of the regulatory mechanisms controlling Ca(2+) homeostasis during cardiomyocyte development.
Calcium ; physiology ; Calcium Channels ; metabolism ; physiology ; Calcium Signaling ; Heart ; embryology ; Homeostasis ; physiology ; Humans ; Intracellular Fluid ; physiology ; Myocytes, Cardiac ; metabolism ; physiology

OBJECTIVETo investigate the underlying mechanism for the selective modulation of the permeability of blood-tumor barrier (BTB) by small dose of bradykinin (BK).

METHODSC6 glioma cells were treated with BK, and changes of intracellular nitric oxide (NO) and intracellular calcium level were measured with fluorescent spectrophotometer.

RESULTSThe initial application of BK easily triggered extracellular calcium influx, which resulted in intracellular calcium store release in C6 glioma cells. The above mechanism was also named ryanodine mediated calcium induced calcium release (CICR). We also detected a long-lasting intracellular NO elevation in C6 glioma cells upon BK treatment. Further study showed that ryanodine mediated CICR contributed greatly to the secondary NO elevation induced by BK treatment.

CONCLUSIONThese results suggested that BK triggered CICR in C6 glioma cells and the associated NO generation might be the underlying mechanism for the selective modulation of BTB permeability by BK.

Animals ; Bradykinin ; pharmacology ; Calcium ; metabolism ; Cell Line, Tumor ; Glioma ; pathology ; Intracellular Fluid ; drug effects ; Nitric Oxide ; metabolism ; Rats ; Ryanodine ; pharmacology ; Spectrometry, Fluorescence ; methods ; Time Factors

OBJECTIVETo investigate the effect of Congsheng Capsule (CSC) in intracellular Ca2+ concentration in cerebral intra-synaptosomes of ischemia/reperfusion mice and analogous ischemic injured neurons to estimate the mechanism of CSC in antagonizing ischemic cerebral injury.

METHODSThe concentration of Ca2+ in cerebral intra-synaptosomes of mice and in neurocyte suspension of fetal mice were determined using Fura-2/AM double wavelength fluorescence spectrophotometer.

RESULTSCSC 3 g/kg and 9 g/kg through gastrogavage could relieve the degree of calcium overloading of intra-synaptosomes in mice after cerebral ischemia/reperfusion. The CSC containing serum could inhibit the elevation of Ca2+ content in neurocytes induced by 1 hour hypoxia and glutamate of high concentration (200 mumol/L).

CONCLUSIONCSC plays a role in antagonizing ischemic injury through relieving the calcium overloading after cerebral ischemia.

Animals ; Brain ; metabolism ; Brain Ischemia ; metabolism ; Calcium ; metabolism ; Calcium Channel Blockers ; therapeutic use ; Capsules ; Drugs, Chinese Herbal ; therapeutic use ; Female ; Intracellular Fluid ; metabolism ; Male ; Mice ; Neuroprotective Agents ; therapeutic use ; Phytotherapy ; Rats ; Rats, Wistar ; Reperfusion Injury ; metabolism ; Synaptosomes ; metabolism

Resveratrol (trans-3, 4', 5-trihydroxy stilbene), a phytoalexin found in grape skins and red wine, has been reported to have a wide range of biological and pharmacological properties. It has been speculated that resveratrol may have cardioprotective activity. The objective of our study was to investigate the effects of resveratrol on intracellular calcium concentration ([Ca(2+)](i)) in rat ventricular myocytes. [Ca(2+)](i) was detected by laser scanning confocal microscopy. The results showed that resveratrol (15~60 mumol/L) reduced [Ca(2+)](i) in normal and Ca(2+)-free Tyrode's solution in a concentration-dependent manner. The effects of resveratrol on [Ca(2+)](i) in normal Tyrode's solution was partially inhibited by pretreatment with sodium orthovanadate (Na3VO4, 1.0 mmol/L, P<0.01), an inhibitor of protein tyrosine phosphatase, or L-type Ca(2+) channel agonist Bay K8644 (10 mumol/L, P<0.05), but could not be antagonized by NO synthase inhibitor L-NAME (1.0 mmol/L). Resveratrol also markedly inhibited the ryanodine-induced [Ca(2+)](i) increase in Ca(2+)-free Tyrode's solution (P<0.01). When Ca(2+) waves were produced by increasing extracellular Ca(2+) concentration from 1 to 10 mmol/L, resveratrol (60 mumol/L) could reduce the velocity and duration of propagating waves, and block the propagating waves of elevated [Ca(2+)](i). These results suggest that resveratrol may reduce the [Ca(2+)](i) in isolated rat ventricular myocytes. The inhibition of voltage-dependent Ca(2+) channel and tyrosine kinase, and alleviation of Ca(2+) release from sarcoplasmic reticulum (SR) are possibly involved in the effects of resveratrol on rat ventricular myocytes. These findings could help explain the protective activity of resveratrol against cardiovascular disease.
Animals ; Calcium ; metabolism ; Calcium Channels ; drug effects ; Heart Ventricles ; cytology ; metabolism ; Intracellular Fluid ; drug effects ; metabolism ; Male ; Myocytes, Cardiac ; drug effects ; metabolism ; Protein-Tyrosine Kinases ; drug effects ; Rats ; Rats, Sprague-Dawley ; Sarcoplasmic Reticulum ; drug effects ; metabolism ; Stilbenes ; pharmacology

Inflammatory responses are strictly regulated by coordination of pro-inflammatory and anti-inflammatory mediators. Interleukin-4 (IL-4) and interleukin-10 (IL-10) have typically the biologic anti-inflammatory effects on monocytes, but uncertain effects on polymorphonuclear leukocytes (PMNs). The PMNs are the first line of cellular response for host defense during acute inflammation. To modify hyper-inflammatory reaction with biologic anti-inflammatory mediators, we have determined the biologic anti-inflammatory activities of IL-4 and IL-10 on human PMNs. Human PMNs were pretreated with IL-4 or IL-10 and then stimulated with formyl methionyl leucyl phenylalanine (fMLP) for times indicated. The level of H2O2, interleukin-8 (IL-8) and tumor necrosis factor-alpha (TNF-alpha) were determined in the each cell free supernatants. fMLP plays the role of a typical pro-inflammatory agent and, at least in determined conditions, down-regulated TNF release. IL-4 acts as an anti-inflammatory mediator but IL-10 did not show its anti-inflammatory activities on fMLP-stimulated human PMNs. IL-4 and IL-10 have different anti-inflammatory mechanisms. Perhaps, IL-10 needs co-factors to act as an anti-inflammatory mediator.
Cells, Cultured ; Humans ; Hydrogen Peroxide/metabolism ; Interleukin-10/*pharmacology ; Interleukin-4/*pharmacology ; Interleukin-8/metabolism ; Intracellular Fluid ; N-Formylmethionine Leucyl-Phenylalanine/pharmacology ; Neutrophils/cytology/*drug effects/immunology ; Tumor Necrosis Factor-alpha/metabolism

The effects of estriol on oxygen uptake, glucose release, lactate and pyruvate production, beta-hydroxybutyrate and acetoacetate production in perfused rat liver as well as, carbon uptake in rat liver and intracellular calcium in isolated Kupffer cells were investigated. Basal oxygen consumption of perfused liver increased significantly in estriol or ethanol-treated rats. But these increased effects were blocked by gadolinium chloride pretreatment. In a metabolic study, pretreatment with estriol resulted in a decrease in glucose production and in glycolysis while an increase in ketogenesis. A more oxidized redox state of the mitochondria was indicated by increased ratios of perfusate [lactate]/[pyruvate] and decreased ratios of perfusate [beta-hydroxybutyrate]/[acetoacetate]. Carbon uptake of Kupffer-cell increased significantly in estriol-treated rats. But these increased uptake were not shown in rats pre-treated by gadolinium chloride blocking phagocytosis. In isolated Kupffer cells from estriol-treated rats, intracellular calcium was more significantly increased after addition of lipopolysaccharide (LPS) than in controls. These findings suggest that the metabolic effects of estriol (two mg per 100 mg body wt) can be summarized to be highly toxic in rat liver, and these findings suggest that oral administration of estrogens may induce hepatic dysfunctions and play a role in the development of liver disease.
3-Hydroxybutyric Acid/metabolism ; Acetoacetates/metabolism ; Animal ; Calcium/metabolism ; Carbohydrates/metabolism ; Carbon/metabolism ; Cells, Cultured ; Colloids/metabolism ; Estriol/pharmacology* ; Estriol/metabolism ; Ethanol/pharmacology ; Female ; Gadolinium/pharmacology ; Glucose/biosynthesis ; Intracellular Fluid/metabolism ; Kupffer Cells/metabolism ; Kupffer Cells/cytology ; Lactates/metabolism ; Lipids/metabolism ; Liver/metabolism ; Liver/drug effects* ; Oxygen Consumption ; Phagocytosis ; Pyruvic Acid/metabolism ; Rats ; Rats, Sprague-Dawley

The Na(+)-Ca(2+) exchange is a major pathway for removal of cytosolic Ca(2+) in cardiac myocytes. To explore the effects of temperature, intracellular Na(+), ATP and pH on Na(+)-Ca(2+) exchange currents (I(Na/Ca)) of intact guinea-pig myocytes, the whole-cell patch-clamp technique was used to record I(Na/Ca) in isolated guinea-pig ventricular myocytes. We found that I(Na/Ca) at 34 degrees C was four times higher than that at 22 degrees C. However, intracellular acidification had no obvious influence on bidirectional I(Na/Ca). At 22~24 degrees C , intracellular ATP depletion and intracellular acidification did not markedly affect bidirectional I(Na/Ca) either. At 34~37 degrees C , intracellular ATP depletion and intracellular acidification synergistically inhibited the outward and inward currents of I(Na/Ca), and blocked the inward currents of I(Na/Ca)more potently than the outward currents of I(Na/Ca). The effect of ATP on I(Na/Ca) is temperature-dependent. Intracellular higher sodium increased the outward currents of I(Na/Ca) however it did not increase, even sometimes decreased the inward currents of I(Na/Ca). These results suggest that intracellular ATP depletion and intracellular acidification synergistically impair Ca(2+) extrusion via forward mode Na(+)-Ca(2+) exchange, and intracellular sodium overload increases Ca(2+) influx via reverse mode Na(+)-Ca(2+) exchange, leading to calcium overload respectively.
Adenosine Triphosphate ; physiology ; Animals ; Calcium ; metabolism ; Guinea Pigs ; Heart Ventricles ; cytology ; pathology ; Hydrogen-Ion Concentration ; Hypoxia ; physiopathology ; Intracellular Fluid ; physiology ; Male ; Myocytes, Cardiac ; metabolism ; physiology ; Patch-Clamp Techniques ; Sodium ; physiology ; Sodium-Calcium Exchanger ; physiology ; Temperature

Mitofusin2 (Mfn2) plays a pivotal role in the proliferation and apoptosis of vascular smooth muscle cells (VSMCs). The purpose of this study was to investigate the effects of Mfn2 on the trafficking of intracellular cholesterol in the foam cells derived from rat VSMCs (rVSMCs) and also to investigate the effects of Mfn2 on the expression of adenosine triphosphate-binding cassette subfamily A member 1 (ABCA1), adenosine triphosphate-binding cassette subfamily G member 1 (ABCG1) and peroxisome proliferator-activated receptor gamma (PPARγ). The rVSMCs were co-cultured with oxidized low density lipoprotein (LDL, 80 μg/mL) to produce foam cells and cholesterol accumulation in cells. Before oxidized LDL treatment, different titers (20, 40 and 60 pfu/cell) of recombinant adenovirus containing Mfn2 gene (Adv-Mfn2) were added into the culture medium for 24 h to transfect the Mfn2 gene into the rVSMCs. Then the cells were harvested for analyses. The protein expression of Mfn2 was significantly higher in Adv-Mfn2-transfected group than in untransfected group (P<0.05), and the expression levels significantly increased when the titer of Adv-Mfn2 increased (P<0.05). At 24 or 48 h after oxidized LDL treatment, rVSMCs became irregular and their nuclei became larger, and their plasma abounded with red lipid droplets. However, the number of red lipid droplets was significantly decreased in Adv-Mfn2-transfected group as compared with untransfected group. At 48 h after oxidized LDL treatment, the intracellular cholesterol in rVSMCs was significantly increased (P<0.05), but it was significantly decreased in Adv-Mfn2-transfected group as compared with untransfected group (P<0.05), and it also significantly decreased when the titer of Adv-Mfn2 increased (P<0.05). The mRNA and protein expression levels of ABCA1 and ABCG1 were significantly increased in Adv-Mfn2-transfected group as compared with untransfected group (P<0.05). Though the mRNA and protein expression levels of PPARγ was not significantly increased (P>0.05), the phosporylation levels of PPARγ were significantly decreased in Adv-Mfn2-transfected group as compared with untransfected group (P<0.05). These results suggest that the transfection of Adv-Mfn2 can significantly reduce intracellular cholesterol in oxidized LDL-induced rVSMCs possibly by decreasing PPARγ phosporylation and then increasing protein expression levels of ABCA1 and ABCG1, which may be helpful to suppress the formation of foam cells.
ATP Binding Cassette Transporter 1 ; metabolism ; ATP Binding Cassette Transporter, Sub-Family G, Member 1 ; ATP-Binding Cassette Transporters ; metabolism ; Animals ; Cell Differentiation ; physiology ; Cells, Cultured ; Cholesterol ; metabolism ; Foam Cells ; cytology ; metabolism ; Intracellular Fluid ; metabolism ; Lipoproteins, LDL ; metabolism ; Membrane Proteins ; genetics ; metabolism ; Mitochondrial Proteins ; genetics ; metabolism ; Muscle, Smooth, Vascular ; cytology ; metabolism ; Oxidation-Reduction ; PPAR gamma ; metabolism ; Rats

OBJECTThe authors studied the influence of CO(2) pneumoperitoneum on intracellular pH and signal transduction arising from cancer cell multiplication in laparoscopic tumor operation.

METHODThey set up a simulation of pneumoperitoneum under different CO(2) pressure, and then measured the variation of intracellular pH (pHi) at different time and the activity of protein kinase C (PKC) and protein phosphatase 2a (PP2a) at the end of the pneumoperitoneum. After 1 week, the concentration of cancer cells in the culture medium was calculated.

RESULTWhen the pressure of CO(2) pneumoperitoneum was 0, 10, 20, 30 mmHg respectively, the average pHi was 7.273, 7.075, 6.783, 6.693 at the end of the pneumoperitoneum; PKC activity was 159.4, 168.5, 178.0, 181.6 nmol/(g.min) and PP2a was 4158.3, 4066.9, 3984.0, 3878.5 nmol/(g.min) respectively. After 1 week, the cancer cells concentration was 2.15 x 10(5), 2.03 x 10(5), 2.20 x 10(5), 2.18 x 10(5) L(-1).

CONCLUSIONCO(2) pneumoperitoneum could promote acidosis in cancer cells, inducing the activation of protein kinase C and deactivation of protein phosphatase 2a, but it could not accelerate the mitosis rate of the cancer cells.

Animals ; Breast Neoplasms ; chemistry ; metabolism ; Carbon Dioxide ; administration & dosage ; Cell Line, Tumor ; Cell Proliferation ; drug effects ; Cell Survival ; drug effects ; Enzyme Activation ; drug effects ; Hydrogen-Ion Concentration ; Intracellular Fluid ; chemistry ; Phosphoprotein Phosphatases ; metabolism ; Pneumoperitoneum, Artificial ; methods ; Protein Kinase C ; metabolism ; Protein Phosphatase 2 ; Rats ; Signal Transduction ; drug effects

AIMTo compare the effects of salvianolic acid B (Sal B) and Ginkgo biloba extract EGb 761 on beta-amyloid peptide (beta-AP) fibril formation and cytotoxicity to PC12 cells.

METHODSThe inhibitory effects of Sal B and EGb 761 on beta-AP1-40 fibril formation were determined by using fluorescence analysis with Thioflavin T (ThT) and electron microscopic image. beta-AP25-35 was aged by incubating at 37 degrees C for 7 d, then the protein was incubated with PC12 cells. The protective effects of Sal B and EGb 761 against cytotoxicity induced by aged beta-AP25-35 in PC12 cells were evaluated by MTT reduction assay and flow cytometric analysis. beta-AP25-35-induced accumulation of intracellular reactive oxygen species (ROS) was determined by fluorescence analysis.

RESULTSBoth Sal B and EGb 761 inhibited the formation of amyloid fibrils, protected PC12 cells from beta-AP25-35-induced cytotoxicity, and decreased ROS accumulation caused by beta-AP25-35. The effective doses of Sal B were far lower than those of EGb 761.

CONCLUSIONSal B was much more efficient than EGb 761 in inhibiting beta-AP aggregation and in protecting PC12 cells from beta-AP-induced cytotoxicity.

Amyloid beta-Peptides ; chemistry ; toxicity ; ultrastructure ; Animals ; Apoptosis ; drug effects ; Benzofurans ; isolation & purification ; pharmacology ; Cell Survival ; drug effects ; Dose-Response Relationship, Drug ; Drugs, Chinese Herbal ; isolation & purification ; pharmacology ; Flow Cytometry ; Ginkgo biloba ; chemistry ; Intracellular Fluid ; drug effects ; metabolism ; Microscopy, Electron ; Neuroprotective Agents ; isolation & purification ; pharmacology ; PC12 Cells ; Peptide Fragments ; chemistry ; toxicity ; ultrastructure ; Plant Extracts ; isolation & purification ; pharmacology ; Plants, Medicinal ; chemistry ; Rats ; Reactive Oxygen Species ; metabolism ; Salvia miltiorrhiza ; chemistry