Scutellarin (SCU), a flavonoid from a traditional Chinese medicinal plant. Our previous study has demonstrated that SCU relaxes mouse aortic arteries mainly in an endothelium-depend-ent manner. In the present study, we investigated the vasoprotective effects of SCU against HR-induced endothelial dysfunction (ED) in isolated rat CA and the possible mechanisms involving cyclic guanosine monophosphate (cGMP) dependent protein kinase (PKG). The isolated endothelium-intact and endothelium-denuded rat CA rings were treated with HR injury. Evaluation of endothelium-dependent and -independent vasodilation relaxation of the CA rings were performed using wire myography and the protein expressions were assayed by Western blotting. SCU (10-1 000 μmol·L(-1)) could relax the endothelium-intact CA rings but not endothelium-denuded ones. In the intact CA rings, the PKG inhibitor, Rp-8-Br-cGMPS (PKGI-rp, 4 μmol·L(-1)), significantly blocked SCU (10-1 000 μmol·L(-1))-induced relaxation. The NO synthase (NOS) inhibitor, NO-nitro-L-arginine methylester (L-NAME, 100 μmol·L(-1)), did not significantly change the effects of SCU (10-1 000 μmol·L(-1)). HR treatment significantly impaired ACh-induced relaxation, which was reversed by pre-incubation with SCU (500 μmol·L(-1)), while HR treatment did not altered NTG-induced vasodilation. PKGI-rp (4 μmol·L(-1)) blocked the protective effects of SCU in HR-treated CA rings. Additionally, HR treatment reduced phosphorylated vasodilator-stimulated phosphoprotein (p-VASP, phosphorylated product of PKG), which was reversed by SCU pre-incubation, suggesting that SCU activated PKG phosphorylation against HR injury. SCU induces CA vasodilation in an endothelium-dependent manner to and repairs HR-induced impairment via activation of PKG signaling pathway.
Animals ; Apigenin ; pharmacology ; Cell Adhesion Molecules ; drug effects ; Cell Hypoxia ; Coronary Vessels ; drug effects ; Cyclic GMP ; analogs & derivatives ; metabolism ; pharmacology ; Cyclic GMP-Dependent Protein Kinases ; Glucuronates ; pharmacology ; Microfilament Proteins ; drug effects ; NG-Nitroarginine Methyl Ester ; metabolism ; pharmacology ; Phosphoproteins ; drug effects ; Rats ; Rats, Sprague-Dawley ; Reperfusion Injury ; complications ; physiopathology ; Signal Transduction ; drug effects ; Thionucleotides ; metabolism ; pharmacology ; Vasodilation ; drug effects ; physiology

A growing number of studies have shown that arginine vasopressin (AVP) plays an analgesia role in the modulation of nociception. Previous studies have focused on the central mechanisms of AVP analgesia. The aim of the present study was to find out whether peripheral mechanisms are also involved. The effect of AVP on GABA-activated currents (IGABA) and GABAA receptor function in freshly isolated dorsal root ganglion (DRG) neurons of rats were studied using whole cell patch clamp technique. The result showed that, IGABA were potentiated by pre-treatment with AVP (1 × 10⁻¹⁰-1 × 10⁻⁵ mol/L) in a concentration-dependent manner. Meanwhile, the GABA concentration-response curve was shifted upwards, with an increase of (49.1 ± 4.0)% in the maximal current response but with no significant change in the EC50 values. These results indicate that the enhancing effect is non-competitive. In addition, the effects of AVP on IGABA might be voltage-independent. This potentiation of IGABA induced by AVP was almost completely blocked by the V1a receptor antagonist SR49059 (3 × 10⁻⁶ mol/L). Also it could be removed by intracellular dialysis of either GDP-β-S (5 × 10⁻⁴mol/L), a non-hydrolyzable GDP analog, or GF109203X (2 × 10⁻⁶ mol/L), a selective protein kinase C (PKC) inhibitor, with the re-patch clamp. These results suggest that AVP up-regulates the function of the GABAA receptor via G protein-coupled receptors and PKC-dependent signal pathways in rat DRG neurons, and this potentiation may underlie the analgesia induced by AVP.
Animals ; Arginine Vasopressin ; pharmacology ; Ganglia, Spinal ; cytology ; Guanosine Diphosphate ; analogs & derivatives ; pharmacology ; Indoles ; Maleimides ; Membrane Potentials ; Neurons ; drug effects ; Patch-Clamp Techniques ; Rats ; Rats, Sprague-Dawley ; Receptors, GABA-A ; metabolism ; Signal Transduction ; Thionucleotides ; pharmacology ; gamma-Aminobutyric Acid ; pharmacology

This study is to observe the difference in pharmacological characteristics between circular smooth muscles of rat isolated gastric body and gastric fundus, and to investigate the effects of nucleoside and nucleotide on circular smooth muscle of the rat gastric body and the involved receptors. Circular muscle strips of the rat gastric body and gastric fundus were prepared, and contractile responses to agonists were investigated with a technique of drug-receptor interaction in functional system. There was no significant difference between the circular muscle strips of the gastric body and gastric fundus in the responses to KCl, and no difference in EC50 values of contractile responses for 5-HT and His between the two kinds of preparations (P > 0.05). However, Emax values of contractile responses to 5-HT and His [(0.81 +/- 0.26) and (0.88 +/- 0.27) g] in gastric body were significantly smaller than those in gastric fundus [(2.67 +/- 0.61) and (1.90 +/- 0.68) g, P < 0.01], and EC50 value of CCh produced contractile response [(0.45 +/- 0.15) micromol x L(-1)] in gastric body was significantly higher than that in gastric fundus [(0.20 +/- 0.09) micromol x L(-1), P < 0.01]. In precontracted circular muscle strips of the gastric body, ATP (0.1-3000 micromol x L(-1)) produced only a contractile response concentration-dependently, but the same concentration of ATP induced a biphasic response (relaxation followed by a contraction) in precontracted circular muscle strips of the gastric fundus. ATP, UTP, ADP, 2-MeSATP and alpha,beta-MeATP produced contractile responses concentration-dependently in circular muscle strips of the rat gastric body. The EC50 value for 2-MeSATP [(7.2 +/- 5.2) nmol x L(-1)] was about 500 times lower than that for Ach [(3.47 +/- 1.20) micromol x L(-1)]. The rank order of potency for the contraction was 2-MeSATP>ADP>ATP=UTP>alpha,beta-MeATP>adenosine. The contractile responses to ATP and UTP were not significantly affected by phentolamine, propranolol, atropine or tetrodotoxin. In conclusion, there is a significant difference in pharmacological characteristics between the circular smooth muscles of the rat gastric body and gastric fundus and nucleotides might be important mediators responsible for the contraction via a specific P2Y receptor in circular smooth muscle of the rat gastric body.
Adenosine ; pharmacology ; Adenosine Diphosphate ; pharmacology ; Adenosine Triphosphate ; analogs & derivatives ; pharmacology ; Animals ; Gastric Fundus ; drug effects ; physiology ; Male ; Muscle Contraction ; drug effects ; Muscle, Smooth ; drug effects ; physiology ; Purinergic P2 Receptor Agonists ; Rats ; Rats, Wistar ; Receptors, Purinergic P2 ; drug effects ; Stomach ; drug effects ; physiology ; Thionucleotides ; pharmacology ; Uridine Triphosphate ; pharmacology

This study was aimed to investigate the possible effects of cyclic adenosine monophosphate (cAMP) analogue 8-(4-chlorophenylthio) adenosine 3', 5'-cyclic monophosphate (8-CPT-cAMP) on the M(2b) subtype of acute myeloid leukemia (AML-M(2b)) cells. AML-M(2b) is characterized by the non-random chromosome translocation t (8; 21) (q22; q22), through which AML1 (acute myeloid leukemia 1) gene on chromosome 21 is fused with ETO (eight twenty-one) gene on chromosome 8, coding correspondent AML1-ETO fusion protein, which plays a crucial role in the leukemogenesis of AML-M(2b). The AML-M(2b) cell line Kasumi-1 cells were used as an in vitro model. The influences of 8-CPT-cAMP on the proliferation and differentiation of Kasumi-1 cells were evaluated according to cellular morphology, changes in cell surface antigen and cell cycle, as well as nitroblue-tetrazolium (NBT) assay. Meanwhile, semi-quantity RT-PCR and Western blot assay were used to detect the degradation of AML1-ETO fusion protein in Kasumi-1 cells before and after the treatment. The results showed that 8-CPT-cAMP (200 micromol/L) could significantly inhibit cell growth and induce differentiation of Kasumi-1 cells. However, it must be pointed out that 8-CPT-cAMP-induced differentiation in Kasumi-1 is not a typical terminal differentiation. Furthermore, 8-CPT-cAMP exerted little influence on the expression of AML1-ETO fusion gene and its product in Kasumi-1 cells. In conclusion, the 8-CPT-cAMP induced differentiation in Kasumi-1 cells. This results may provide experimental and theoretical basis for the breakthrough of differentiation-induced therapy extended to another leukemia.
Cell Transformation, Neoplastic ; drug effects ; Core Binding Factor Alpha 2 Subunit ; genetics ; metabolism ; Cyclic AMP ; analogs & derivatives ; pharmacology ; Humans ; Leukemia, Myeloid, Acute ; genetics ; metabolism ; pathology ; Oncogene Proteins, Fusion ; genetics ; metabolism ; RUNX1 Translocation Partner 1 Protein ; Thionucleotides ; pharmacology ; Tumor Cells, Cultured

Previously we demonstrated that ATP released from LPS-activated microglia induced IL-10 expression in a process involving P2 receptors, in an autocrine fashion. Therefore, in the present study we sought to determine which subtype of P2 receptor was responsible for the modulation of IL-10 expression in ATP-stimulated microglia. We found that the patterns of IL-10 production were dose-dependent (1, 10, 100, 1,000 micrometer) and bell-shaped. The concentrations of ATP, ATP-gammaS, ADP, and ADP-beta S that showed maximal IL-10 release were 100, 10, 100, and 100 micrometer respectively. The rank order of agonist potency for IL-10 production was 2'-3'-O-(4-benzoyl)-benzoyl ATP (BzATP) = dATP > 2-methylthio-ADP (2-meSADP). On the other hand, 2-methylthio-ATP (2-meSATP), alpha,beta-methylene ATP (alpha,beta-meATP), UTP, and UDP did not induce the release of IL-10 from microglia. Further, we obtained evidence of crosstalk between P2 receptors, in a situation where intracellular Ca2+ release and/or cAMP-activated PKA were the main contributors to extracellular ATP-(or ADP)-mediated IL-10 expression, and IL-10 production was down- regulated by either MRS2179 (a P2Y1 antagonist) or 5'-AMPS (a P2Y11 antagonist), indicating that both the P2Y1 and P2Y11 receptors are major receptors involved in IL-10 expression. In addition, we found that inhibition of IL-10 production by high concentrations of ATP-gammaS (100 micrometer) was restored by TNP-ATP (an antagonist of the P2X1, P2X3, and P2X4 receptors), and that IL-10 production by 2-meSADP was restored by 2meSAMP (a P2Y12 receptor antagonist) or pertusis toxin (PTX; a Gi protein inhibitor), indicating that the P2X1, P2X3, P2X4 receptor group, or the P2Y12 receptor, negatively modulate the P2Y11 receptor or the P2Y1 receptor, respectively.
Adenosine Diphosphate/analogs & derivatives/pharmacology ; Adenosine Triphosphate/analogs & derivatives/*pharmacology ; Adenylate Cyclase/antagonists & inhibitors ; Animals ; Calcium/metabolism ; Chelating Agents/pharmacology ; Cyclic AMP-Dependent Protein Kinases/antagonists & inhibitors ; Enzyme Inhibitors/pharmacology ; Extracellular Space/drug effects/*metabolism ; Gene Expression Regulation/drug effects ; Interleukin-10/*biosynthesis ; Microglia/*drug effects/enzymology/*metabolism ; RNA, Messenger/genetics/metabolism ; Rats ; Rats, Sprague-Dawley ; Receptor Cross-Talk/*drug effects ; Receptors, Purinergic P2/agonists/antagonists & inhibitors/genetics/*metabolism ; Thionucleotides/pharmacology

OBJECTIVETo study the effect of phosphorothioate antisense Bcl-xL oligodeoxynucleotides on apoptosis and thermosensitivity of BcaCD885 cells.

METHODSAfter phosphorothioate antisense Bcl-xL oligodeoxynucleotides were transfected into BcaCD885 cells. The characteristics of apoptotic cells were evaluated by morphological observation and TUNEL staining. Apoptotic rate and Bcl-xL protein expression were analyzed with flow cytometry. The influence of phosphorothioate antisense Bcl-xL oligodeoxynucleotides on apoptotic rate of BcaCD885 cells induced by hyperthermia with 43 degrees C 40 min was also examined through flow cytometry.

RESULTSThe BcaCD885 cells transfected with phosphorothioate antisense Bcl-xL oligodeoxynucleotides displayed apoptotic morphological features. The Bcl-xL protein expression level of these cells was down-regulated significantly compared with the controlled group (P < 0.05). The apoptotic rate of these cells induced by hyperthermia was increased significantly compared with the controlled group (P < 0.05).

CONCLUSIONPhosphorothioate antisense Bcl-xL oligodeoxynucleotides can induce apoptosis and improve thermosensitivity of BcaCD885 cells.

Apoptosis ; drug effects ; Flow Cytometry ; Gene Expression Regulation, Neoplastic ; drug effects ; genetics ; Hot Temperature ; Humans ; Hyperthermia, Induced ; Mouth Neoplasms ; genetics ; pathology ; Oligodeoxyribonucleotides, Antisense ; pharmacology ; Oligonucleotides, Antisense ; genetics ; pharmacology ; Proto-Oncogene Proteins c-bcl-2 ; genetics ; metabolism ; Thionucleotides ; pharmacology ; Transfection ; Tumor Cells, Cultured ; bcl-X Protein

To explore dose-effect or time-effect of vascular endothelial growth factor (VEGF) antisense phosphorothioate oligodeoxynucleotides (AS PS-ODN) on growth of HL-60 cells, and to study the effect mechanism so as to find new role of VEGF, A7, which was the most effective one of AS PS-ODN selected with computer-aided design and experimental assay, contains 20-DNA modified with phosphorothioate and was tranferred into cells mediated with lipofectin. After culture for 72 hours, inhibitive rate of cell growth was detected with MTT methods, viable cells were counted with trypan blue exclusion each 24 hour, cell configuration and apoptosis were observed with Geimsa staining and flow cytometry respectively, level of VEGF protein was detected with VEGF ELISA kit. The results showed that A7 is able to inhibit cell growth of HL-60 in dose-depending manner of AS PS-ODN, to down-regulate VEGF protein expression significantly, and not to induce apoptosis of HL-60 cells. It is concluded that there is possibility that the inhibition effect of VEGF AS PS-ODN on HL-60 cell growth is to restrain cell proliferation without inducing apoptosis of HL-60 cell, which would interpret that endogenous VEGF proteins have a capacity of promoting proliferation of HL-60 cell.
Cell Proliferation ; drug effects ; Flow Cytometry ; HL-60 Cells ; Humans ; Oligonucleotides, Antisense ; pharmacology ; Thionucleotides ; pharmacology ; Vascular Endothelial Growth Factor A ; analysis ; physiology

In order to investigate the role of non-adrenergic non-cholinergic nerves in regulating mechanical and electrical activity of gastric circular smooth muscle, the effects of ATP and its analogues on gastric motility and electrical activities were observed in guinea-pig. In organ bath system, isometric force of the circular smooth muscle of guinea-pig gastric antrum was measured. Electrical activity of the muscle was recorded by using intracellular microelectrode. Electrical and mechanical activities were recorded by chart recorder. ATP and 2-MeSATP potentiated the mechanical activity but did not affect electrical activity in gastric circular smooth muscle. ATP and 2-MeSATP-induced contraction was effectively blocked by nonselective P2y-purinoceptor antagonist, reactive-blue-2 and suramin, but ATP-induced contraction was not blocked by alpha,beta-MeATP-induced desensitization of P2x-purinoceptors. However, alpha,beta-MeATP, P2x-purinoceptor agonist, attenuated slow waves with membrane hyperpolarization and inhibited contraction. The relaxation by beta,gamma-MeATP was blocked by alpha,beta-MeATP-induced desensitization of P2x-purinoceptors. ATP-induced contraction was blocked by external calcium-free, but not by nicardipine, a L-type calcium channel blocker. Indomethacin, a nonselective cyclooxygenase inhibitor, did not block ATP-induced contraction. The results suggest that: (1) ATP- and analogues-induced contraction is mediated by P2y-purinoceptor, whereas alpha,beta-MeATP-induced relaxation by P2x-purinoceptor in guinea-pig gastric antral circular smooth muscle. (2) ATP-induced contraction is dependent on extracellular calcium, but Ca2+ entry is not mediated by L-type calcium channel. (3) Prostaglandins are not involved in ATP- and analogue-induced contraction of gastric circular smooth muscle in guinea-pigs, and alpha,beta-MeATP-induced relaxation is related to membrane hyperpolarization.
Adenosine Triphosphate ; analogs & derivatives ; pharmacology ; Animals ; Electrophysiology ; Guinea Pigs ; In Vitro Techniques ; Microelectrodes ; Muscle Contraction ; drug effects ; physiology ; Muscle, Smooth ; drug effects ; physiology ; Purinergic Agonists ; Pyloric Antrum ; drug effects ; physiology ; Thionucleotides ; pharmacology

OBJECTIVETo study the potential anti-tumor effect of telomerase inhibitors.

METHODSHuman oral squamous carcinoma cell line KB was selected as target cell. The effects of 3'-azido-3'-deoxythymidine (AZT) and human antisense phosphorothioate (AS-ONS) for telomerase template on KB cell line were investigated. The cytotoxic effect of AZT and AS-ONS on tumor cells was quantified using MTT colorimetric assay. Assay of 3H-TdR incorporation was undertaken to measure the cell proliferation. The changes of telomerase activity after treatment was detected and quantified by telomeric repeat amplification protocol (TRAP) semi-quantitative analysis. The Flow Cytometry was used to detect apoptosis and measure cell cycle.

RESULTSBoth AZT and AS-ONS inhibited the growth of KB cell line in a certain range of concentrations, and meanwhile the telomerase activity was reduced after treatment. In addition, both AZT and AS-ONS can induce apoptosis and arrest G1 phase of cell cycle.

CONCLUSIONThe results obtained above indicated that AZT and AS-ONS could be potentially used as an anti-oral carcinoma agent or an auxiliary treatment for cancer. Those inhibitory effects might be partially due to the induction of apoptosis and the prolongation of cell cycle.

Antineoplastic Agents ; pharmacology ; Carcinoma, Squamous Cell ; pathology ; Cell Division ; drug effects ; Enzyme Inhibitors ; pharmacology ; Humans ; Mouth Neoplasms ; pathology ; Oligodeoxyribonucleotides ; pharmacology ; Telomerase ; antagonists & inhibitors ; metabolism ; Thionucleotides ; Tumor Cells, Cultured ; Zidovudine ; pharmacology

OBJECTIVETo investigate the potential effects of arsenic trioxide (As(2)O(3)) combined with 8-(4-chlorophenylthio) adenosine 3', 5'-cyclic monophosphate (8-CPT-cAMP) on the retinoic acid (RA)-resistant acute promyelocytic leukemia (APL) cells.

METHODSThe RA resistant APL cell lines NB4-R1 and NB4-R2 were used as in vitro models. The effect of As(2)O(3) and/or 8-CPT-cAMP was evaluated according to cellular morphology, cell surface antigen and nitroblue-tetrazolium (NBT) assay. Meanwhile, immunofluorescence analysis and Western blot assay were used to detect the degradation of PML-RAR alpha fusion protein and the change of several key cell cycle regulatory proteins in these cells before and after the treatment.

RESULTSLow dose of As(2)O(3) (0.25 micromol/L) synergized with 8-CPT-cAMP (200 micromol/L) in inducing differentiation of NB4-R1 and NB4-R2 cells, while neither of these two drugs alone could induce differentiation of these cells. In addition, 8-CPT-cAMP was able to inhibit the cell growth by modulating the expression of some important cell cycle regulators and to facilitate the As(2)O(3)-mediated degradation of PML-RAR alpha fusion protein.

CONCLUSIONSAs(2)O(3) combined with 8-CPT-cAMP could induce differentiation of RA-resistant APL cells.

Antineoplastic Agents ; pharmacology ; Arsenicals ; pharmacology ; Cell Differentiation ; drug effects ; Cell Line, Tumor ; Cyclic AMP ; analogs & derivatives ; pharmacology ; Dose-Response Relationship, Drug ; Drug Resistance, Neoplasm ; Drug Synergism ; Humans ; Leukemia, Promyelocytic, Acute ; pathology ; Oxides ; pharmacology ; Thionucleotides ; pharmacology ; Tretinoin ; pharmacology