Effects of calcium ionophore A23187 on proliferation ,cycle and expression of caspase-3 in hepatic stellate cells stimulated by transforming growth factor-β1 / 西安交通大学学报(医学版)

Objective To study the effect of calcium ionophore A23187 on the proliferation , cycle and expression of caspase-3 in rat hepatic stellate cells by stimulated transforming growth factor Bata 1 (TGF-β1 ) . Methods Hepatic stellate cells were cultured in 37 ℃ and 50 mL/L CO2 incubator .The cells were divided into 5 groups:blank group ,TGF-β1 (5 ng/mL) group ,TGF-β1 +low-,medium-and high-dose calcium ionophore A23187 groups:5 ng/mL TGF-β1 stimulation for 24 h ,and then 1μmol/L ,2μmol/L and 4 μmol/L of calcium ion carrier A23187 was added and treated for 24 h .The cells proliferation was detected by MTT .The cell cycle was detected by flow cytometry and the expression of caspase-3 was detected by immunoblotting .Results Different concentrations of calcium ionophore A23187 could significantly inhibit the proliferation of cells ( P< 0 .05 ) . And the dose of calcium ionophore A23187 increased ;RGR in the low-,medium-and high-dose groups was 85 .93% ,61 .71% ,and 48 .43% (P<0 .05) .There was significant difference between the two groups (P<0 .05) .The higher the dose of calcium ionophore A23187 ,the higher the proportion of G1 phase cells ,the lower the ratio of S+ G2 cells ( P<0 .05) ,with significant difference (P<0 .05) .With the increase of calcium ionophore A23187 concentration ,the expression of caspase-3 protein increased significantly ( P< 0 .05 ) . Conclusion Calcium ionophore A23187 prevents hepatic stellate cells from G1 phase to S phase and G2 phase ,inhibits its proliferation and up-regulates the expression of caspase-3 .

Emodin Isolated from Polygoni cuspidati Radix Inhibits TNF-alpha and IL-6 Release by Blockading NF-kappaB and MAP Kinase Pathways in Mast Cells Stimulated with PMA Plus A23187

Emodin, a naturally occurring anthraquinone derivative isolated from Polygoni cuspidati radix, has several beneficial pharmacologic effects, which include anti-cancer, anti-diabetic, and anti-inflammatory activities. In this study, the authors examined the effect of emodin on the production of proinflammatory cytokines, such as, tumor necrosis factor (TNF)-alpha and interleukin (IL)-6, in mouse bone marrow-derived mast cells (BMMCs) stimulated with phorbol 12-myristate 13-acetate (PMA) plus the calcium ionophore A23187. To investigate the mechanism responsible for the regulation of pro-inflammatory cytokine production by emodin, the authors assessed its effects on the activations of transcriptional factor nuclear factor-kappaB (NF-kappaB) and mitogen-activated protein kinases (MAPKs). Emodin attenuated the nuclear translocation of (NF)-kappaB p65 and its DNA-binding activity by reducing the phosphorylation and degradation of IkappaBalpha and the phosphorylation of IkappaB kinase B (IKK). Furthermore, emodin dose-dependently attenuated the phosphorylations of MAPKs, such as, extracellular signal-regulated kinase 1/2 (ERK1/2), p38 MAP kinase, and the stress-activated protein kinases (SAPK)/c-Jun-N-terminal kinase (JNK). Taken together, the findings of this study suggest that the anti-inflammatory effects of emodin on PMA plus A23187-stimulated BMMCs are mediated via the inhibition of NF-kappaB activation and of the MAPK pathway.

Involvement of throm box aneA2 and tyrosine kinase in the synergistic interaction of platelet activating factor and calcium ionophore A23187 in human platelet aggregation

The present study was carried out to examine the mechanisms of the synergistic interaction of PAF and A23187 mediated platelet aggregation. We found that platelet aggregation mediated by subthreshold concentrations of PAF (5 nM) and A23187 (1 micrometer) was inhibited by PAF receptor blocker (WEB 2086, IC50=0.65 micrometer) and calcium channel blockers, diltiazem (IC50=13 micrometer) and verapamil (IC50=18 micrometer). Pretreatment of platelets with PAF and A23187 induced rise in intracellular calcium and this effect was also blocked by verapamil. While examining the role of the down stream signaling pathways, we found that platelet aggregation induced by the co-addition of PAF and A23187 was also inhibited by low concentrations of phospholipase C (PLC) inhibitor (U73122; IC50 = 10 micrometer), a cyclooxygenase inhibitor (indomethacin; IC50=0.2 micrometer) and inhibitor of TLCK, herbimycin A with IC50 value of 5 micrometer. The effect was also inhibited by a specific TXA2 receptor antagonist, SQ 29548 with very low IC50 value of 0.05 micrometer. However, the inhibitors of MAP kinase, PD98059 and protein kinase C, chelerythrine had no effect on PAF and A23187-induced platelet aggregation. These data suggest that the synergism between PAF and A23187 in platelet aggregation involves activation of thromboxane and tyrosine kinase pathways.

Induction of acrosome reaction by calcium ionophore A23187 in sperm separated by two-layer percoll gradient method.

The aim of this study was to compare thepercentages of sperm with an acrosome reaction between those with and without calcium ionophore A23187 induction after two-layer Percoll gradient separation. Thirty normal semen samples were obtained from the male partners of infertile couples attending the Infertility Clinic at Siriraj Hospital. After the process of sperm separation by two-layer Percoll gradient technique, the final samples samples were divided into 2 portions. An aliquot of 10 ตM of calcium ionophore A23187 was added to one portion to induce an acrosome reaction, while the other portion was used as a control. Fluorescein isothiocyanate-conjugated Pisum sativam agglutinin (FITC-PSA) staining was performed on both specimens and the acrosome reated-sperm were evaluated. The percentage of acrosome-reated sperm in the calcium ionophore A23187 induced group was significantly higher than those of the control group (24.8+6.6vs 15.4+6.0;p < 0.001). It is concluded that calcium ionophore can significantly induce an acrosome reaction on sperm separated by two-layer Percoll gradient technique, and it may be beneficial to add calcium ionophore A23187 to sperm preparation for use in IUI or IVF.

A23187—Channel behaviour: Fluorescence study.

Pyranine entrapped soylipid liposomes have been used as a model system to study the proton transport across membrane in the presence of A23187, a carboxylic ionophore specific for electroneutral exchange of divalent cations. An apparent rate constant (kapp) for transport of protons has been determined from the rate of change of fluorescence intensity of pyranine by stopped flow rapid kinetics in the presence of proton gradient The variation of kapp has been studied as a function of ionophore concentration and the results have been compared with gramicidin—a well known channel former under the similar experimental conditions. The rates thus obtained showed that A23187 is not only a simple carrier but also shows channel behaviour at high concentration of ionophore.

Effect of diazepam on the oxytocin induced contraction of the isolated rat uterus / 영남의대학술지

This study was designed to investigate the effect of diazepam on the spontaneous contraction and oxytocin induced contraction of the isolated rat uterus. Female rat (Sprague-Dawley) pretreated with oophorectomy and 4 days administration of estrogen. Weighing about 200 g, was sacrificed by cervical dislocation, and the uteruses were isolated. A longitudinal muscle strip was placed in temperature controlled (37℃) muscle chamber containing Locke's solution and myographied isometrically. Diazepam inhibited the spontaneous contraction and oxytocin induced contraction of the isolated rat uterus in a concentration-dependent manner. GABA, muscimol, a GABA A receptor agonist, bicuculline, a competitive GABA A receptor antagonist, picrotoxin, a non competitive GABA A receptor antagonist, baclofen, a GABA B receptor agonist, and delta-aminovaleric acid, a GABA B receptor antagonist, did not affect on the spontaneous and oxytocin induced contraction of the isolated rat uterus. The inhibitory actions of diazepam on the spontaneous and oxytocin induced contraction were not affected by all the GABA receptor agonists and antagonists, but exceptionally potentiated by bicuculline. This potentiation-effect by bicuculline was not antagonized by muscumol. In normal calcium PSS, addition of calcium restored the spontaneous contraction preinhibited by diazepam and recovered the contractile of oxtrocin preinhibited by diazepam. A23187, a calcium inophore, enhanced the restoration of both the spontaneous and oxytocin induced contraction by addition of calcium. In calcium-free PSS, diazepam suppressed the restoration of spontaneous motility by addition of calcium but allowed the recovery of spontaneous motility to a considerable extent. Diazepam could not inhibit some development of contractility by oxytocin in calcium-free PSS, but inhibited the increase in contractility by subsequent addition of calcium. These results suggest that the inhibitory action of diazepam on the rat uterine motility does not depend on or related to GABA receptors and that diazepam inhibits the extracellular calcium influx to suppress the spontaneous and oxytocin induced contractilities.

INFLUENCE OF bPTH ( 1-34 ) ON PGI_2 RELEASE FROM HEART CELLS / 中国药理学通报

In order to explore the mechanism of cardiac damage by PTH, the release of PGI2 from heart cells was measured. The results showed that bPTH ( 1-34) increased the release of 6-keto-PGFla from heart cells in a dose dependent manner. Calcium inophone A23187 also increased the 6-keto-PGF1? release, while EDTA and verapamil reduced it. These suggest that the PGI2 synthesis in heart cells was affected by intra and extracellular calcium. The significance of bPTH( 1-34) induced increase of PGI2 synthesis might be associated with interference of energy metabolism, and then, cell damage.

Rescue activation of calcium ionophore A23187 on unfertilized human oocytes after conventional in-vitro fertilization and intracytoplasmic sperm injection / 中国病理生理杂志

AIM: To explore the activation effect of calcium ionophore A23187 on unfertilized human mature oocytes after conventional in-vitro fertilization (IVF) and intracytoplasmic sperm injection (ICSI). METHODS: Thirty-seven unfertilized mature oocytes from IVF and 41 after ICSI were included in our experiment. They were incubated in 5 ?mol/L calcium ionophore A23187 for 5 minutes. Second polar body extrusion and pronuclear formation were recorded 12-16 hours later. The activated oocytes were cultured for another 2 days in vitro. RESULTS: Activation rate of unfertilized oocytes from conventional IVF and ICSI were 64.9%(24/37)and 73.2%(30/41), respectively. Among 41 unfertilized oocytes after ICSI treated with A23187, 30 were activated and 24 had 2 polar body (PB) and 2 pronuclear (PN). But for the unfertilized oocytes from conventional IVF only 20% activated oocytes had 2 PN and 2 PB. The percentage difference of oocytes containing 2 PB and 2 PN between the two groups was significant ( P