OBJECTIVETo test the different contrctile responses of extracellular nucleotides, such as ATP, UTP and nucleotide uridine adenosine tetraphosphate (Up4A) in gastric longitudinal muscle (LM) and circular muscle (CM). Examined the effect of P2X and P2Y receptor antagonists (in this study, we used IP5I and suramin) and cyclooxygenase inhibitor (indomethacin) on Up4A induced contractile responses in LM and CM.

METHODSThe rats were sacrificed and the stomachs were opened to gain LM and CM. Using organ bath system to assess contrctile responses of smooth muscle.

RESULTSUp4A could induce contractile responses in both CM and LM, which were similar with ATP and UTP. IP5 did not attenuate Up4A could induce contractions in both LM and CM, but suramin and indomethacin significantly inhibited Up4A contraction in CM, but not in LM.

CONCLUSIONOur results suggest that extracellular nucleosides and their inhibitors induce different responses between LM and CM.

Adenosine Triphosphate ; pharmacology ; Animals ; Dinucleoside Phosphates ; pharmacology ; Indomethacin ; Muscle Contraction ; Muscle, Smooth ; physiology ; Nucleotides ; pharmacology ; Rats ; Suramin ; Uridine Triphosphate ; pharmacology

AIM AND METHODSTo further explore the functions of alveolar macrophage and their modulation mechanisms, the activity of lysozyme in rat alveolar macrophage assessed by electrophoresis was determined. The effects of androsterone and estradiol on lysozyme secretion and their mechanisms were also studied.

RESULTSThe results showed that androsterone and estradiol increased activity of lysozyme significantly (P < 0.01), indomethacin abolished those effects. This suggests that the insufficiency of sex hormones secretion as the retrogression of gonads is involved in the decrease of immunological functions, and the susceptibility to infectious diseases.

CONCLUSIONSex hormones increased activity of lysozyme, and those effects related to prostaglandin.

Androsterone ; pharmacology ; Animals ; Estradiol ; pharmacology ; Female ; Indomethacin ; pharmacology ; Macrophages, Alveolar ; drug effects ; enzymology ; secretion ; Male ; Muramidase ; metabolism ; Rats ; Rats, Wistar

OBJECTIVETo determine the role of a pharmacokinetic interaction in the protective effect of curcumin against the gastric damage induced by indomethacin administration as such or as its prodrug acemetacin.

METHODSWistar rats orally received single dose of indomethacin (30 mg/kg) with and without curcumin (30 mg/kg); gastric injury was evaluated by determining the total damaged area. Additional groups of rats received an oral single dose of indomethacin (30 mg/kg) or its prodrug acemetacin (34.86 mg/kg) in the presence or absence of curcumin (30 mg/kg). Indomethacin and acemetacin concentrations in plasma from blood draws were determined by high-performance liquid chromatography.Plasma concentration-against-time curves were constructed, and bioavailability parameters, maximal concentration (C) and area under the curve to the last sampling time (AUC) were estimated.

RESULTSConcomitant administration of indomethacin and curcumin resulted in a significantly reduced gastric damage compared to indomethacin alone. However, co-administration of curcumin did not produce any significant alteration in the bioavailability parameters of indomethacin and acemetacin after administration of either the active compound or the prodrug.

CONCLUSIONCurcumin exhibits a protective effect against indomethacin-induced gastric damage, but does not produce a reduction of the bioavailability of this nonsteroidal anti-inflammatory drug, indomethacin. Data thus suggest that a pharmacokinetic mechanism of action is not involved in curcumin gastroprotection.

Animals ; Biological Availability ; Curcumin ; pharmacology ; Drug Interactions ; Indomethacin ; analogs & derivatives ; pharmacokinetics ; toxicity ; Male ; Rats ; Rats, Wistar

This study was designed to clarify the dependency of hypoxic coronary vasodilation (HCD) on the endothelium and the role of the K+ channels on HCD in the rabbit coronary artery. HCD was investigated in an isolated left circumflex coronary artery precontracted with prostaglandin F2 alpha. Vascular rings were suspended for isometric tension recording in an organ chamber filled with Krebs-Henseleit (KH) solution. Hypoxia was induced by gassing the chamber with 95% N2 + 5% CO2 and was maintained for 15 approximately 25 min. Hypoxia elicited a vasodilation in the precontracted coronary artery with and without endothelium. There was no difference between the amplitude of the HCD induced by two consecutive hypoxic challenges and the effects of 20% O2 + 5% CO2 + 75% N2 and 95% O2 + 5% CO2 control K-H solution of subsequent responses to hypoxia. Inhibition of the cyclooxygenase pathway by treatment with indomethacin had no effect on HCD. Blockades of the tetraethylammonium chloride-sensitive K+ channel abolished HCD. Apamin, a blocker of the small conductance Ca(2+)-activated K+ (KCa) channel, and iberiotoxin, a blocker of the large conductance KCa channel had no effect on HCD, respectively. Glibenclamide, a blocker of the ATP-sensitive K+ (K+ATP) channel, reduced HCD. Cromakalim, an opener of the K+ATP channel, relaxed the coronary artery precontracted with prostaglandin F2 alpha. The degree of relaxation by cromakalim was similar to that by hypoxia while glibenclamide reduced both hypoxia- and cromakalim-induced vasodilatations. In conclusion, these results suggest that HCD is independent on endothelium and HCD is considered to be induced by activation of K+ATP channel.
Animal ; Anoxia/physiopathology* ; Coronary Vessels/physiopathology* ; Coronary Vessels/drug effects ; Cyclooxygenase Inhibitors/pharmacology ; Enzyme Inhibitors/pharmacology ; Female ; Indomethacin/pharmacology ; Male ; Nitroarginine/pharmacology ; Rabbits ; Tetraethylammonium/pharmacology ; Vasodilation/physiology*

Rabbit eyes were irradiated with a neodymium-yttrium-aluminum-garnet (Nd-YAG) laser and the changes in prostaglandin E and protein levels in the aqueous humor were measured. Intraocular pressure and pupil diameter were also determined in the same rabbits. Prostaglandin E and protein in the aqueous humor were increased depending upon the number of laser lesions. The increase in intraorular pressure and the decrease in pupil diameter occurred at similar dosages of laser irradiation. The response of the iris to the photodisruption was rapid. Changes in prostaglandin and protein contents and pupil diameter were already prominent 15 min after laser irradiation. Indomethacin pretreatment abolished most of these responses, suggesting that acute reactions following photodisruption were largely dependent on prostaglandin synthesis in iris tissue
Administration, Topical ; Animals ; Aqueous Humor/*analysis ; Female ; Indomethacin/*pharmacology ; Iris/*surgery ; Laser Therapy ; *Light Coagulation ; Male ; Prostaglandins E/*analysis ; Rabbits

The aim of this paper was to observe the combination therapy with total triterpenoids of Chaenomeles speciosa and omeprazole on indomethacin-induced gastric ulcer in rats, and explore its possible mechanism. Rats were randomly divided into normal group, model group, omeprazole monotherapy(3.6 mg·kg~(-1)) group, total triterpenoids of C. speciosa monotherapy(100 mg·kg~(-1)) group, total triterpenoids of C. speciosa and omeprazole combination therapy(100 mg·kg~(-1)+3.6 mg·kg~(-1)) group. Except for the normal group, the other groups were given indomethacin(20 mg·kg~(-1)) by oral once a day for 7 consecutive days. Then the treated groups were given corresponding drugs by gavage, once a day for 14 consecutive days. The next day after the last administration, half of the rats in each group were measured the gastric mucosal blood flow, gastric juice volume and serum TNF-α, IL-1β, IL-6, IL-4 and IL-10. After the remaining rats in each group were underwent pyloric ligation 4 hours after the last administration, the gastric endocrine volume, pH value and total acidity of gastric secretion were measured, then histological analysis was performed, MPO activity, cAMP content and histomorphological analysis were conducted. Real-time PCR was applied to detect the mRNA expressions of gastric tissue TNF-α,IL-1β, IL-6, IL-4, IL-10, VEGFA, A_(2A)R; the protein expressions of VEGFA, A_(2A)R, PKA, p-PKA, CREB, p-CREB, EGF, EGFR, p-EGFR, MUC6, TFF2 in gastric tissue were detected by Western blot. The results indicated that total triterpenoids of C. speciosa and omeprazole combination therapy might significantly increase gastric mucosal blood flow, gastric mucus volume, reduce gastric endocrine volume, secretion acidity and mucosal damage, decrease the levels of TNF-α,IL-1β and IL-6, increase the levels of IL-4 and IL-10 in blood and gastric tissue, inhibit the activity of MPO, increase the content of cAMP in gastric tissue, up-regulate the mRNA expressions of VEGFA, A_(2A)R and protein expressions of VEGFA, A_(2A)R, PKA, p-PKA, CREB, p-CREB, EGF, EGFR, p-EGFR, MUC6, TFF2 in gastric tissue, elevate p-PKA/PKA, p-CREB/CREB and p-EFGR/EFGR. Moreover, the combination therapy with total triterpenoids of C. speciosa and omeprazole was more obvious than those of two monotherapies. These aforementioned findings suggested that the combination therapy with total triterpenoids of C. speciosa and omeprazole on indomethacin-induced gastric ulcer have significant therapeutic effect on indomethacin induced gastric ulcer in rats, its mechanism might be related to regulating A_(2A)R/AKT/CREB, A_(2A)R/VEGFA, EGF/EGFR and MUC6/TFF2 signaling pathways, inhibiting pro-inflammatory factors, increasing gastric mucosal blood flow, up-regulating mucosal cell proliferation factors and promoting mucosal protective factors.
Animals ; Cytokines ; Gastric Mucosa ; Indomethacin ; Omeprazole ; pharmacology ; Phytochemicals ; pharmacology ; Random Allocation ; Rats ; Rosaceae ; chemistry ; Stomach Ulcer ; chemically induced ; drug therapy ; Triterpenes ; pharmacology ; Tumor Necrosis Factor-alpha

Although hypoxic pulmonary vasoconstriction (HPV) has been recognized by many researchers, the precise mechanism remains unknown. As isolated pulmonary arteries will constrict in vitro in the response to hypoxia, the oxygen sensor/transduction mechanism must reside in the pulmonary arterial smooth muscle or in the endothelium, or in both. Unfortunately, much of the current evidence is conflicting, especially as to the dependency of HPV on the endothelium and the role of a K+ channel. Therefore, this experiment was attempted to clarify the dependency of HPV on the endothelium and the role of a K+ channel on HPV in rat pulmonary artery. The effects of hypoxia were investigated in isolated main pulmonary arteries precontracted with norepinephrine. Vascular rings were suspended for isometric tension recording in an organ chamber filled with a Krebs-Henseleit solution. Hypoxia was induced by gassing the chamber with 95% N2 + 5% CO2 and this was maintained for 20 min. Hypoxia elicited a vasoconstriction in arteries with endothelium. Mechanical disruption of the endothelium abolished HPV. There was no difference between the amplitude of the HPV induced by two consecutive hypoxic challenges and the effect of normoxic and hyperoxic control Krebs-Henseleit solution on a subsequent response to hypoxia. Inhibition of NO synthesis by treatment with N(omega)-nitro-L-arginine reduced HPV, but inhibition of a cyclooxygenase pathway by treatment with indomethacin had no effect on HPV. Blockades of a tetraetylammonium chloride-sensitive K+ channel abolished HPV. Verapamil, a Ca2+ entry blocker reduced HPV. In conclusion, these results suggest that HPV was dependent on the endothelium and that HPV can be considered to be induced by inhibition of the mechanisms of NO-dependent vasodilation such as the opening of a K+ channels.
Animal ; Anoxia/physiopathology* ; Blood Vessels/physiopathology ; Calcium Channel Blockers/pharmacology ; Cyclooxygenase Inhibitors/pharmacology ; Enzyme Inhibitors/pharmacology ; Indomethacin/pharmacology ; Nitroarginine/pharmacology ; Pulmonary Circulation/physiology* ; Pulmonary Circulation/drug effects ; Rats ; Tetraethylammonium/pharmacology ; Vasoconstriction/physiology* ; Vasoconstriction/drug effects ; Verapamil/pharmacology

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.
Blood Platelets/*drug effects ; Calcimycin/*pharmacology ; Humans ; Indomethacin/pharmacology ; Ionophores/pharmacology ; Platelet Activating Factor/metabolism/*pharmacology ; Platelet Aggregation/*physiology ; Protein-Tyrosine Kinase/antagonists & inhibitors/*physiology ; Quinones/pharmacology ; Research Support, Non-U.S. Gov't ; Thromboxane A2/*physiology ; Verapamil/pharmacology

AIMTo investigate the regulatory effects of various anti-inflammatory drugs on both endogenous and TNFalpha-induced NF-kappaB activation as well as the relative biological activity.

METHODSHEK293 cells were cultured in 96-well plate and 6-well plate, treated with meloxicam, indomethacin, dexamethasone and hydrocortisone, without or with 10 ng.mL(-1) TNFalpha for 24 hours. Then cell proliferation was measured by MTT and cell apoptosis was analyzed by pI stain-flow cytometry. HEK293/ kappaB-luc cells transfected stably with pElam-kappaB-luc vector, were cultured in 96-well plate and treated as above. Equal amounts of cell lysates were tested for luciferase activity which represents NF-kappaB activation.

RESULTSEndogenous NF-kappaB activation was present in HEK293 cells and its level can be increased about 2 times by 10 ng.mL(-1) TNFalpha-induction. Dexamethasone (1 x 10(-8) mol.L(-1)) and meloxicam (1 x 10(-7) - 1 x 10(-6) mol.L(-1)) can decrease both endogenous and TNFalpha-induced NF-kappaB activation. Hydrocortisone (1 x 10(-9) mol.L(-1)) increases endogenous NF-kappaB activation but decreases TNFalpha-induced one significantly. No influence of indomethacin on endogenous NF-kappaB activation was observed. However, its influence on TNFalpha-induced NF-kappaB activation is needed for further study. Cell apoptosis was observed after treatment with TNFalpha and 1 x 10(-8), 1 x 10(-6) mol.L(-1) dexamethasone and 1 x 10(-7) mol.L(-1) indomethacin, or only with dexamethasone. No significant effect of these anti-inflammatory drugs on cell proliferation was observed.

CONCLUSIONVarious anti-inflammatory drugs differ in their ability to regulate NF-kappaB activation in HEK293 cells, which indicates that NF-kappaB activation might be a potential useful target to study mechanism and for drug screening.

Anti-Inflammatory Agents ; pharmacology ; Apoptosis ; drug effects ; Cell Line ; Cell Proliferation ; drug effects ; Dexamethasone ; pharmacology ; Embryo, Mammalian ; Humans ; Hydrocortisone ; pharmacology ; Indomethacin ; pharmacology ; Kidney ; cytology ; metabolism ; NF-kappa B ; metabolism ; Thiazines ; pharmacology ; Thiazoles ; pharmacology

BACKGROUNDA nonsteroidal anti-inflammatory drug, indomethacin, has been shown to have anti-leukemic activity and induce leukemic cell apoptosis. This study was to elucidate the mechanism of indomethacin-induced K562 cell apoptosis.

METHODSK562 cells were grown in RPMI 1640 medium and treated with different doses of indomethacin (0 micromol/L, 100 micromol/L, 200 micromol/L, 400 micromol/L, 800 micromol/L) for 72 hours. The cells were harvested, and cell viability or apoptosis was analyzed using MTT assay and AO/EB stain, combining laser scanning confocal microscopy (LSCM) technique separately. For the localization and distribution of intracellular caspase-3 or caspase-8 protein, immunofluorescence assay was carried out. To reveal the activation of caspase-3 or caspase-8 in indomethacin-treated cells, Western blot detection was used. The change in intracellular free calcium was determined by Fluo-3/Am probe labeling combined with LSCM.

RESULTSIndomethacin could lead to K562 cell apoptosis and inhibit cell viability in a concentration-dependent manner. An increased expression of intracellular caspase-3 or caspase-8 was observed at higher doses of indomethacin (400 - 800 micromol/L). Western blot results showed upregulation and activation in both caspase-3 and caspase-8 protein. Under indomethacin intervention, the levels of intracellular free calcium showed a significant increase. Blocking the activity of cyclooxygenase did not abolish the effects of indomethacin on K562 cell apoptosis.

CONCLUSIONSActivation and upregulation of caspase-3 or caspase-8 protein were responsible for Indomethacin-induced K562 cell apoptosis. Variation of intracellular free calcium might switch on the apoptotic pathway and the proapoptotic effect of indomethacin might be cyclooxygenase-independent.

Apoptosis ; drug effects ; Calcium ; metabolism ; Caspase 3 ; Caspase 8 ; Caspases ; genetics ; metabolism ; Cyclooxygenase Inhibitors ; pharmacology ; Enzyme Activation ; Gene Expression Regulation, Enzymologic ; drug effects ; Humans ; Indomethacin ; pharmacology ; K562 Cells