OBJECTIVETo evaluate the effects of theanine on sedative effects induced by pentobarbital sodium.

METHODThe locomotor activities of ICR mice induced by theanine (0.25, 0.5, 1.0, 2.0, 4.0 g x kg(-1)), pentobarbital sodium (5, 10 mg x kg(-1)) or the combination of both were determined with video-tracking system, and a novel index: Peripheral active time Peripheral time (PATP) was established. Hypnosis effect of combination of both was tested with right-reflex disappearance.

RESULTCompared with normal saline (74.52 +/- 20.4)%, theanine alone decreased this PATP in dose-dependent manner from (62.03 +/- 21.11)%, (56.44 +/- 21.69)%, (31.13 +/- 17.2)%, (25.06 +/- 10.03)% to (17.21 +/- 7.43)% (P>0.05, P<0.05, P<0.01, P<0.01 and P<0.01, respectively). Compared with pentobarbital sodium (5 mg x kg(-1)), between 0.25 g x kg(-1) and 1.0 g x kg(-1) theanine combined with that decreased peripheral PATP from (28.30 +/- 17.57)%, (30.64 +/- 17.21)% to (24.28 +/- 9.59)% (all P<0.01), and increased by 2.0 g x kg(-1) reversely (61.95 +/- 19.39)%. Compared with normal saline, pentobarbital sodium (10 mg x kg(-1)) and the combination with theanine decreased significantly PATP (all P<0.01). Compared with pentobarbital sodium (10 mg x kg(-1)), 0.25 g x kg(-1) theanine combined with that increased PATP [(25.37 +/- 13.68)% vs (10.08 +/- 7.98)%, P<0.01)] and 0.5 g x kg(-1), 1.0 g x kg(-1) theanine could depresse that increase [(14.56 +/-10.10)%, (8.24 +/- 4.08)% vs (10.08 +/- 7.98)%]. Total distance and peripheral active time showed the same or similar tendency in theanine alone or combination with pentobarbital sodium . Theanine enchanced hypnosis effect of pentobarbital sodium in dose-dependent manner.

CONCLUSIONTheanine can affect the sedative effect of low dose pentobarbital sodium in bidirectional action style but not change the hypnosis effect.

Animals ; Drug Interactions ; Female ; Glutamates ; pharmacology ; Hypnotics and Sedatives ; pharmacology ; Male ; Mice ; Mice, Inbred ICR ; Motor Activity ; drug effects ; Pentobarbital ; pharmacology

BACKGROUNDTumor cells can reduce the number of dendritic cells (DCs) in the tumor environment and cause DC dysfunction through autocrine or paracrine pathways. We sought to measure cyclooxygenase-2 (COX-2) expression in bombesin-inhibited DCs treated with theanine in vitro and to explore the protection and activation effects of theanine on DCs.

METHODSEnzyme-linked immunosorbent assay (ELISA), reverse transcription-polymerase chain reaction (RT-PCR), and Western blotting were used to analyze the effects of theanine on COX-2 expression and interleukin (IL)-12/IL-10 secretion of bombesin-treated DCs.

RESULTSDCs acquired an impaired phenotype as a result of bombesin treatment. Theanine increased the expression of mature DC surface molecules. The number of cell apoptosis with the treatment of bombesin and theanine significantly decreased, accounting for 15.9%, compared with 26.1% of cell apoptosis with bombesin. COX-2 expression in bombesin-treated DCs was inhibited by theanine in a dose-dependent manner. Theanine promoted DC secretion of IL-12. IL-12 levels reached (137.4 ± 4.9) pg/ml with theanine at 200 µmol/L. However, theanine inhibited the secretion of IL-10 in a dose-dependent manner. IL-10 levels were only (58.4 ± 6.9) pg/ml with theanine at 200 µmol/L.

CONCLUSIONTheanine inhibits the transcription and translation of COX-2 and regulates the balance of IL-10/IL-12 secretion in bombesin-inhibited DCs, leading to the recovery of a state of activation in DCs.

Bombesin ; pharmacology ; Cells, Cultured ; Cyclooxygenase 2 ; metabolism ; Dendritic Cells ; drug effects ; metabolism ; Enzyme-Linked Immunosorbent Assay ; Glutamates ; pharmacology ; Humans ; Interleukin-10 ; metabolism ; Interleukin-12 ; metabolism

OBJECTIVETo investigate the sequence-dependent effect of combined use of gemcitabine and pemetrexed on the proliferation of human pancreatic carcinoma cell lines BXPC-3 and PANC-1 in vitro and explore the cellular mechanism.

METHODSMTT assay was used to determine the proliferation of the two cells after addition of the two drugs in different sequences, and the cell cycle changes were analyzed by flow cytometry.

RESULTSBoth gemcitabine (10(-7)-10 mg/ml) and pemetrexed (10(-7)-10 mg/ml) significantly inhibited the proliferation of BXPC-3 and PANC-1 cells in a dose- and time-dependent manner. The effect of combined administration of gemcitabine and pemetrexed on the cell proliferation varied with the order of the drug delivery, and addition of gemcitabine 24 h after pemetrexed administration produced a significant enhancement of the inhibitory effect as compared with simultaneous drug administration (P<0.05) or the administration of the two drugs in a reverse order (P<0.05). Compared with the control group, combined administration of gemcitabine and pemetrexed caused obvious cell cycle arrest at G1 and S phases (P<0.05). Simultaneous administration of the two drugs resulted in significantly reduced G2-phase cells (P<0.05); addition of gemcitabine prior to pemetrexed caused cell cycle arrest in G1 phase (P<0.05), while the reverse caused cell cycle in S phase (P<0.05).

CONCLUSIONBoth gemcitabine and pemetrexed can inhibit the proliferation of BXPC-3 and PANC-1 cells, and their synergetic effect depends on the sequence of their administration. The sequential administration of pemetrexed followed by gemcitabine produces significant synergetic effects against the cell proliferation, which might not be associated with their influence of the cell cycle.

Antimetabolites, Antineoplastic ; pharmacology ; Cell Cycle ; drug effects ; Cell Line, Tumor ; Cell Proliferation ; drug effects ; Deoxycytidine ; analogs & derivatives ; pharmacology ; Dose-Response Relationship, Drug ; Drug Synergism ; Glutamates ; pharmacology ; Guanine ; analogs & derivatives ; pharmacology ; Humans ; Pancreatic Neoplasms ; pathology ; Pemetrexed

AIMTo investigate the effect of iptakalim (Ipt), a novel ATP-sensitive potassium channel opener (KATPCO), on astrocyte glutamate uptake activity. The mechanism of action involved was also examined.

METHODSPrimary cultures of astrocytes were prepared from cerebral cortexes of 1 to 2 days old Sprague-Dawley rats. Cultures were preincubated with iptakalim of various concentrations with the absence or presence of 6-hydroxydopamine (6-OHDA, 50 micromol x L(-1)). Then, the cells were treated with pinacidil (10 micromol x L(-1), K+ channel opener) instead of iptakalim and pretreated with glibenclamide (20 micromol x L(-1), ATP-sensitive K+ channel inhibitor) before pinacidil or iptakalim was added into the medium so that the mechanism of action of iptakalim could be analysed. Astrocyte glutamate uptake activity was determined by intracellular concentration of 3H labeled D,L-glutamate, using isotope techniques.

RESULTSBoth iptakalim and pinacidil were shown to increase glutamate uptake activity of astrocytes and reverse inhibitory effect induced by 6-OHDA. But the increased and reversed effects of iptakalim or pinacidil on astrocytic glutamate uptake were found to be completely antagonized by glibenclamide.

CONCLUSIONThese data indicated that iptakalim can enhance astrocytic glutamate uptake activity due to its K+ channel opening properties and lessen glutamate excitotoxicity. Iptakalim may be useful for the therapy of Parkinson's disease.

Animals ; Animals, Newborn ; Astrocytes ; drug effects ; metabolism ; Cells, Cultured ; Cerebral Cortex ; cytology ; Glutamates ; metabolism ; Glyburide ; antagonists & inhibitors ; Neuroprotective Agents ; pharmacology ; Oxidopamine ; antagonists & inhibitors ; Pinacidil ; pharmacology ; Propylamines ; pharmacology ; Rats ; Rats, Sprague-Dawley ; Vasodilator Agents ; pharmacology

By using Fura-2/AM, the effects of magnesium (Mg2+) on the glutamate-induced increase of intracellular free calcium ([Ca2+]i) in the cultured hippocampal neurons and the features were investigated by integrated photoelectric detecting system. The experiments were designed to three groups (The drug was spit to the cells for 20 s): Group A receiving 1 x 10(-5) mol/L glutamate; Group B receiving 1 x 10(-5) mol/L glutamate and 1 x 10(-5) mol/L Mg2+ simultaneously; Group C receiving 1 x 10(-5) mol/L glutamate again after [Ca2+]i in group B back to the baseline. The results showed that in group A, [Ca2+]i was obviously increased. In group B, the changes in [Ca+] i and the peak value were significantly decreased. Moreover, the elevation of Phase 1 was slowed down and Phase 2 was shortened to some extent, and the plateau phase between them was relatively prolonged. In group C, calcium oscillation similar to that in group A occurred, but both the Phase 1 and Phase 2 were shortened and the delta[Ca2+]i was slightly decreased. It was suggested that Mg2+ could quickly inhibit the rise of [Ca2+]i induced by glutamate in the cultured hippocampal neurons in rats.
Animals ; Animals, Newborn ; Biological Transport, Active ; drug effects ; Calcium ; metabolism ; Cells, Cultured ; Fura-2 ; pharmacology ; Glutamates ; pharmacology ; Hippocampus ; cytology ; metabolism ; Magnesium ; pharmacology ; Neurons ; cytology ; metabolism ; Rats ; Rats, Sprague-Dawley

BACKGROUNDDicycloplatin is a relatively safe third generation platinum-complex anti-cancer drug. The present study focused on the effects of dicycloplatin on in vitro proliferation and apoptosis of human aortic smooth muscle cells (HASMC) and human aortic endothelial cells (HAEC).

METHODSProliferation of HASMC and HAEC, DNA content, and cellular levels of proliferation- and apoptosis-related proteins were assessed using the (3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium) (MTS) assay, flow cytometry and Western blotting assays, respectively.

RESULTSDicycloplatin at 10 ng/ml significantly inhibited HASMC proliferation, however, 10 µg/ml were required to significantly inhibit HAEC proliferation. Cell cycle analysis showed that dicycloplatin was a non-specific inhibitor of the cell cycle. Although dicycloplatin significantly decreased proliferating cell nuclear antigen (PCNA) expression in HASMC at all concentrations tested, it did not significantly affect PCNA expression in HAEC; Bax and p53 protein expression was upregulated in dicycloplatin groups.

CONCLUSIONSDicycloplatin at nanogram concentrations significantly inhibits HASMC proliferation, although the effect is relatively weaker than that of sirolimus. In contrast, the effect of dicycloplatin on inhibition of HAEC proliferation is much less pronounced than that on HASMC. The latter characteristics point to the potential for use of dicycloplatin in drug-eluting stents.

Aorta ; cytology ; Blotting, Western ; Cell Proliferation ; drug effects ; Drug Combinations ; Drug-Eluting Stents ; Endothelial Cells ; cytology ; drug effects ; Flow Cytometry ; Glutamates ; pharmacology ; Humans ; Muscle, Smooth, Vascular ; cytology ; drug effects ; Organoplatinum Compounds ; pharmacology ; Sirolimus ; pharmacology

Oxidative stress and apoptosis are the key factors that limit the hypothermic preservation time of donor hearts to within 4-6 h. The aim of this study was to investigate whether the histone deacetylase 3 (HDAC3) inhibitor RGFP966 could protect against cardiac injury induced by prolonged hypothermic preservation. Rat hearts were hypothermically preserved in Celsior solution with or without RGFP966 for 12 h followed by 60 min of reperfusion. Hemodynamic parameters during reperfusion were evaluated. The expression and phosphorylation levels of mammalian STE20-like kinase-1 (Mst1) and Yes-associated protein (YAP) were determined by western blotting. Cell apoptosis was measured by the terminal deoxynucleotidyl-transferase (TdT)-mediated dUTP nick-end labeling (TUNEL) method. Addition of RGFP966 in Celsior solution significantly inhibited cardiac dysfunction induced by hypothermic preservation. RGFP966 inhibited the hypothermic preservation-induced increase of the phosphorylated (p)-Mst1/Mst1 and p-YAP/YAP ratios, prevented a reduction in total YAP protein expression, and increased the nuclear YAP protein level. Verteporfin (VP), a small molecular inhibitor of YAP-transcriptional enhanced associate domain (TEAD) interaction, partially abolished the protective effect of RGFP966 on cardiac function, and reduced lactate dehydrogenase activity and malondialdehyde content. RGFP966 increased superoxide dismutase, catalase, and glutathione peroxidase gene and protein expression, which was abolished by VP. RGFP966 inhibited hypothermic preservation-induced overexpression of B-cell lymphoma protein 2 (Bcl-2)-associated X (Bax) and cleaved caspase-3, increased Bcl-2 mRNA and protein expression, and reduced cardiomyocyte apoptosis. The antioxidant and anti-apoptotic effects of RGFP966 were cancelled by VP. The results suggest that supplementation of Celsior solution with RGFP966 attenuated prolonged hypothermic preservation-induced cardiac dysfunction. The mechanism may involve inhibition of oxidative stress and apoptosis via inactivation of the YAP pathway.
Acrylamides/pharmacology* ; Animals ; Apoptosis/drug effects* ; Cryopreservation ; Disaccharides/pharmacology* ; Electrolytes/pharmacology* ; Glutamates/pharmacology* ; Glutathione/pharmacology* ; Heart/physiology* ; Heart Transplantation/methods* ; Hepatocyte Growth Factor/antagonists & inhibitors* ; Histidine/pharmacology* ; Histone Deacetylase Inhibitors/pharmacology* ; Intracellular Signaling Peptides and Proteins/antagonists & inhibitors* ; Male ; Mannitol/pharmacology* ; Oxidative Stress/drug effects* ; Phenylenediamines/pharmacology* ; Proto-Oncogene Proteins/antagonists & inhibitors* ; Rats ; Rats, Sprague-Dawley ; Signal Transduction/drug effects* ; YAP-Signaling Proteins

This study was aimed to investigate the mechanisms underlying the modulation effect of Mas-related gene (Mrg) C receptors (MrgC) on morphine tolerance. Saline, morphine (20 μg), morphine plus bovine adrenal medulla 8-22 (BAM8-22, 1 nmol) or (Tyr(6))-2-MSH-6-12 (MSH, 5 nmol) were administered intrathecally in rats for 6 days. Pain-related molecules in the spinal cord and dorsal root ganglion (DRG) were examined using Western blot, immunocytochemistry and RT-PCR techniques. The results showed that intrathecal administration of the selective MrgC receptor agonists (BAM8-22 or MSH) remarkably attenuated or abolished chronic morphine-evoked reduction in glutamate transporters (GLAST, GLT-1 and EAAC1) in the spinal cord and increase in neuronal nitric oxide synthase (nNOS) in the spinal cord as well as DRG. In addition, MrgC receptor-like immunoreactivity (IR) was detected in superficial laminae of the spinal cord. Chronic morphine induced significant increases in MrgC receptor-IR in the spinal cord and MrgC receptor mRNA levels in DRG. These results suggest that the modulation of pro-nociceptive mediators in the spinal cord and DRG underlies the inhibition of morphine tolerance by MrgC receptor activation.
Amino Acid Transport System X-AG ; metabolism ; Animals ; Drug Tolerance ; Ganglia, Spinal ; metabolism ; Glutamates ; Morphine ; pharmacology ; Nitric Oxide Synthase Type I ; metabolism ; Pain ; Pain Measurement ; Peptide Fragments ; pharmacology ; Rats ; Rats, Sprague-Dawley ; Receptors, G-Protein-Coupled ; metabolism ; Spinal Cord ; metabolism

OBJECTIVETo study the effects of theanine on dopamine (DA), 5-hydroxy tryptamine (5-TH) and glutamate receptor 2 (GluR2) mRNA, phospholipase-γ1 (PLC-γ1) mRNA in cerebral ischemia-reperfusion injury rats and explore the mechanism of protective effects of theanine on the induced brain injury by ischemia-reperfusion in rats.

METHODSAccording to random number table, a total of 56 sprague-dawley rats in SPF grade about six-week old and 100 - 120 grams weighting were divided into five groups according to the body weight levels: model group (n = 12), sham-operation group (n = 8), low theanine group (10 mg/kg), middle theanine group (30 mg/kg) and high theanine group (90 mg/kg). There were 12 rats in each of the theanine group. The rats in model group and sham-operation groups were given distilled water, and the rats in theanine groups were given corresponding theanine solution intragastrically for fifteen days. Then the cerebral ischemia-reperfusion injury was established by middle cerebral artery occlusion (MCAO). The score of neurological behavior was evaluated at the 3rd and 24th hours after reperfusion. Rats were sacrificed at 24 hours after reperfusion, the concentrations of DA, 5-HT and theanine in rats brain following ischemia-reperfusion were determined. At the same time, we determined the levels of reactive oxygen species (ROS) and activities of catalase (CAT) in mitochondria of brain. The expressions of GluR2 mRNA and PLC-γ1 mRNA in rat brain were examined by reverse transcription polymerase chain reaction (RT-PCR) technique.

RESULTSThe score of neurological behavior of rats in model group, theanine-low, middle, high dose groups at the 3rd hour was 6.000 ± 0.926, 4.100 ± 0.738, 3.444 ± 0.726 and 2.250 ± 0.886 respectively (F = 29.70, P < 0.01), and the score at the 24th hour in these groups was 6.625 ± 0.916, 5.000 ± 0.817, 3.667 ± 0.707 and 2.625 ± 0.916 respectively(F = 34.68, P < 0.01). The concentration of DA in model group, theanine-low, middle, high dose groups and sham-operation group was (10.26 ± 1.12), (12.48 ± 1.09), (14.55 ± 0.94), (15.97 ± 0.92) and (11.98 ± 0.63) µg/g respectively (F = 43.76, P < 0.01). The concentration of 5-HT in these groups was (1.091 ± 0.160), (0.818 ± 0.101), (0.571 ± 0.050), (0.453 ± 0.111) and (0.863 ± 0.063) µg/g respectively (F = 48.68, P < 0.01). The level of ROS was (3.072 ± 0.503), (1.331 ± 0.268), (1.295 ± 0.061), (0.804 ± 0.200) and (2.158 ± 0.218) U×min⁻¹×mg⁻¹ (F = 80.82, P < 0.01) respectively and the activities of CAT in these groups were (4.880 ± 1.121), (8.405 ± 1.356), (9.535 ± 2.511), (15.090 ± 4.054) and (21.260 ± 6.054) U/g respectively (F = 28.58, P < 0.01). The expressions of GluR2 mRNA were 0.842 ± 0.020, 1.063 ± 0.100, 1.170 ± 0.152, 1.254 ± 0.131 and 1.012 ± 0.056 respectively (F = 9.23, P < 0.01). The expressions of PLC-γ1 mRNA in these groups were 0.737 ± 0.090, 0.887 ± 0.045, 0.963 ± 0.025, 0.991 ± 0.049 and 0.867 ± 0.079 respectively(F = 10.24, P < 0.01).

CONCLUSIONTheanine has a protective effect on the induced brain injury by ischemia-reperfusion in rats, which might be associated with its interaction with monoamine neurotransmitters and up-regulating the expressions of GluR2 mRNA and PLC-γ1 mRNA.

Animals ; Biogenic Monoamines ; metabolism ; Brain ; drug effects ; metabolism ; Brain Ischemia ; genetics ; metabolism ; Glutamates ; pharmacology ; Male ; Neurotransmitter Agents ; pharmacology ; Phospholipase C gamma ; genetics ; metabolism ; RNA, Messenger ; genetics ; Rats ; Rats, Sprague-Dawley ; Receptors, AMPA ; genetics ; metabolism ; Reperfusion Injury ; genetics ; metabolism

OBJECTIVETo explore the sensitivity of tumor cell lines with acquired resistance to gefitinib to several chemotherapeutic drugs and provide preclinical basis of available chemotherapy regimens after failure of molecular targeted therapy.

METHODSHuman lung adenocarcinoma cell lines PC9 and PC9/G with acquired resistance to gefitinib were cultured in vitro. The sensitivity to chemotherapeutic drugs and inhibition rate of cell proliferation was determined by MTT assay. Effects of drugs on apoptosis and expression of P-170 were determined by flow cytometry. Difference of gene expression profile between PC9 and PC9/G cells was analyzed by DNA microarray. Western blot was used to test the expression of Akt, phospho-Akt and integrin beta1.

RESULTSThe resistance index of PC9/G cells to cisplatin was about 5.4-fold compared with that of PC9 cells. LY294002 may significantly elevate the sensitivity of PC9/G cells to cisplatin (P < 0.05). PC9/G cells were more sensitive to docetaxel than PC9 cells. No significant difference of sensitivity to pemetrexed was found between these two cell lines. Expression level of P-170 in PC9/G cells was lower than that in PC9 cells. In PC9/G cells, the expression of integrin beta1 and DNA healing gene was high and expression of gene during mitosis was low. The level of expression of Akt, phospho-Akt and integrin beta1 in PC9/G cells was higher than that in PC9 cells.

CONCLUSIONIn PC9/G cells, a cell line with acquired resistance to gefitinib, over-expression of PI3K, integrin and DNA restoration gene and continuous activation of PI3K is found to be correlated with resistance to cisplatin. Docetaxel or pemetrexed is a more reasonable choice than cisplatin for treatment of NSCLC patients who failed to respond to EGFR-TKI.

ATP-Binding Cassette, Sub-Family B, Member 1 ; metabolism ; Antineoplastic Agents ; pharmacology ; Apoptosis ; drug effects ; Carcinoma, Non-Small-Cell Lung ; metabolism ; pathology ; Cell Line, Tumor ; Chromones ; pharmacology ; Drug Resistance, Neoplasm ; Glutamates ; pharmacology ; Guanine ; analogs & derivatives ; pharmacology ; Humans ; Integrin beta1 ; metabolism ; Lung Neoplasms ; metabolism ; pathology ; Morpholines ; pharmacology ; Pemetrexed ; Phosphatidylinositol 3-Kinases ; antagonists & inhibitors ; metabolism ; Proto-Oncogene Proteins c-akt ; metabolism ; Quinazolines ; pharmacology ; Taxoids ; pharmacology