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1.
J Craniofac Surg ; 35(4): e387-e389, 2024 Jun 01.
Article in English | MEDLINE | ID: mdl-38690891

ABSTRACT

Accidentally extruded root canal filler within the sinuses may induce maxillary sinusitis with fungal mass. The authors describe 2 cases of gutta-percha-induced fungal masses in the left maxillary sinus of 2 women. The lesions were evaluated preoperatively using both computed tomography and magnetic resonance imaging, providing comprehensive insights into the condition. In one patient, the lesion was located such that it could be resected through the middle meatal antrostomy alone. However, the second patient presented with an anteroinferiorly situated lesion that necessitated not only a transnasal approach but also an endoscopic modified medial maxillectomy. Both patients recovered uneventfully after surgery. This case series is the first published report of 2 cases of gutta-percha-induced maxillary sinus fungal masses, with their imaging findings, successfully treated through different routes through transnasal endoscopic surgery. These reports highlight the need for a collaborative approach between dental practitioners and otolaryngologists. In addition to the patient's wishes, surgical interventions must consider the unique characteristics of each case and the potential for collaboration across different medical specialties.


Subject(s)
Magnetic Resonance Imaging , Maxillary Sinus , Tomography, X-Ray Computed , Humans , Female , Maxillary Sinus/surgery , Maxillary Sinus/diagnostic imaging , Maxillary Sinus/microbiology , Endoscopy/methods , Gutta-Percha/therapeutic use , Maxillary Sinusitis/surgery , Maxillary Sinusitis/diagnostic imaging , Maxillary Sinusitis/microbiology , Middle Aged , Root Canal Filling Materials/therapeutic use , Adult , Mycoses/surgery , Mycoses/diagnostic imaging , Natural Orifice Endoscopic Surgery/methods
2.
Clin Pract ; 11(1): 43-46, 2021 Jan 29.
Article in English | MEDLINE | ID: mdl-33572824

ABSTRACT

A case of nasopharyngeal tuberculosis with cervical lymph node tuberculosis is reported. The patient was a 20-year-old female immigrant from Vietnam and cook apprentice. Her chief complaint was left neck swelling with pain for three months. She was diagnosed with left neck lymphadenitis at a previous hospital, which suspected malignant lymphoma and referred her to our hospital. At the time of the first visit, she had left lymph swelling with tenderness and granuloma-like masses in the nasopharynx. PET-CT showed accumulations in both the swollen left neck lymph and nasopharynx. The diagnosis of this case would appear to be nasopharyngeal cancer with left and neck lymph node metastasis or nasopharyngeal tuberculosis with cervical lymph node tuberculosis in addition to malignant lymphoma. Based on some examinations (biopsy, bacteria culture, and imaging), it was diagnosed as nasopharyngeal tuberculosis with cervical lymph node tuberculosis. Therefore, she was treated with anti-tuberculosis agent in respiratory medicine.

3.
Clin Pract ; 10(4): 1276, 2020 Oct 15.
Article in English | MEDLINE | ID: mdl-33117516

ABSTRACT

We experienced a case of huge chronic thyroiditis with malignant lymphoma that caused dyspnea with tracheal stenosis, dysphagia with esophagus stenosis and recurrent nerve paralysis. In this case, thyroidectomy was performed and, after the surgery, there was no sign of breathing or swallowing difficulties, and it was confirmed by the postoperative computed tomography that the tracheal stenosis had improved. We considered two possible explanations for the preoperative right recurrent nerve paralysis. In the first, the right recurrent nerve could have suffered from mechanical stimulation such as compression and traction to the recurrent nerve due to enlargement of the malignant lymphoma together with chronic thyroiditis. The second possible explanation was that malignant cells had invaded neurons. We could not distinguish between the two possibilities, since this right recurrent nerve was spared and could not be examined histopathologically.

4.
Biol Pharm Bull ; 36(8): 1278-82, 2013.
Article in English | MEDLINE | ID: mdl-23902972

ABSTRACT

Hydrogen sulfide (H2S), a gasotransmitter, plays a variety of roles in the mammalian body including the cardiovascular system. Given evidence that H2S donors including NaHS inhibit human platelet aggregation, we examined and characterized the effects of NaHS on rabbit platelet aggregation and cytosolic Ca(2+) mobilization. Rabbit platelet aggregation was determined in platelet-rich plasma (PRP) and washed platelets. Intracellular Ca(2+) levels were monitored in Fura2-loaded washed platelets. NaHS prevented rabbit platelet aggregation induced by collagen or ADP, and the effective concentration range of NaHS was 0.1-0.3 mM in PRP and 1-3 mM in washed platelets. In washed platelets, NaHS attenuated cytosolic Ca(2+) mobilization induced by collagen or ADP and also reduced platelet aggregation induced by ionomycin, a Ca(2+) ionophore. The anti-platelet effect of NaHS was blocked by an adenylyl cyclase inhibitor and enhanced by a phosphodiesterase inhibitor. H2S thus suppresses rabbit platelet aggregation by interfering with both upstream and downstream signals of cytosolic Ca(2+) mobilization in a cAMP-dependent manner.


Subject(s)
Hydrogen Sulfide/pharmacology , Platelet Aggregation Inhibitors/pharmacology , Platelet Aggregation/drug effects , Adenosine Diphosphate/pharmacology , Animals , Calcium/metabolism , Collagen/pharmacology , L-Lactate Dehydrogenase/metabolism , Male , Rabbits
5.
J Atheroscler Thromb ; 20(1): 57-64, 2013.
Article in English | MEDLINE | ID: mdl-22972430

ABSTRACT

AIM: The aim of the current study was to investigate circulating adiponectin levels and their associated factors in young lean healthy Japanese women. METHODS: We recruited 82 healthy Japanese women in their twenties and thirties with their body mass index <25 kg/m(2), and performed anthropometric, sphygmomanometric, and laboratory examinations. Laboratory examinations included adiponectin levels, as well as lipid profiles, glucose, hemoglobin A1c, transaminase, and creatinine levels, from which the glomerular filtration rate was estimated (eGFR). RESULTS: The median and interquartile range of circulating adiponectin levels were 8.1 (6.2-10.0) µg/ mL. HDL cholesterol levels and eGFR, but not the other examined clinical parameters, were significantly correlated with log-transformed adiponectin levels; their correlation coefficients were 0.323 (p<0.01) and -0.311 (p<0.01), respectively. Statistical significance was still observed even after adjustment for each other (both p= 0.02). In adjusted models, subjects with HDL cholesterol levels ≥80 mg/dL had 1.3 times higher adiponectin levels than those with 40-60 mg/dL, whereas eGFR ≥110 mL/min/1.73m(2) and 60-90 mL/min/1.73m(2) showed a 1.5-fold difference in adiponectin levels. CONCLUSIONS: Adiponectin levels of young lean healthy Japanese women had significant associations with HDL cholesterol levels and eGFR, even though their HDL cholesterol levels and eGFR were distributed within normal ranges. It seems important to take into account these two variables in evaluating adiponectin levels of these subjects, even if the two variables are within normal ranges.


Subject(s)
Adiponectin/blood , Anthropometry , Adult , Blood Glucose/analysis , Creatinine/blood , Enzyme-Linked Immunosorbent Assay , Female , Glomerular Filtration Rate , Glycated Hemoglobin/analysis , Humans , Lipids/blood , Reference Values
6.
Biochem Biophys Res Commun ; 414(4): 727-32, 2011 Nov 04.
Article in English | MEDLINE | ID: mdl-22001931

ABSTRACT

Hydrogen sulfide (H(2)S), a gasotransmitter, exerts both neurotoxicity and neuroprotection, and targets multiple molecules including NMDA receptors, T-type calcium channels and NO synthase (NOS) that might affect neuronal viability. Here, we determined and characterized effects of NaHS, an H(2)S donor, on cell viability in the primary cultures of mouse fetal cortical neurons. NaHS caused neuronal death, as assessed by LDH release and trypan blue staining, but did not significantly reduce the glutamate toxicity. The neurotoxicity of NaHS was resistant to inhibitors of NMDA receptors, T-type calcium channels and NOS, and was blocked by inhibitors of MEK, but not JNK, p38 MAP kinase, PKC and Src. NaHS caused prompt phosphorylation of ERK and upregulation of Bad, followed by translocation of Bax to mitochondria and release of mitochondrial cytochrome c, leading to the nuclear condensation/fragmentation. These effects of NaHS were suppressed by the MEK inhibitor. Our data suggest that the NMDA receptor-independent neurotoxicity of H(2)S involves activation of the MEK/ERK pathway and some apoptotic mechanisms.


Subject(s)
Apoptosis , Cerebral Cortex/pathology , Hydrogen Sulfide/metabolism , MAP Kinase Signaling System , Receptors, N-Methyl-D-Aspartate/metabolism , Animals , Calcium/metabolism , Cells, Cultured , Cerebral Cortex/drug effects , Cerebral Cortex/metabolism , Mice , Mice, Inbred ICR , Neurons/drug effects , Neurons/metabolism , Neurons/pathology , Receptors, N-Methyl-D-Aspartate/genetics , Sulfides/toxicity , Up-Regulation , bcl-Associated Death Protein/biosynthesis
7.
Toxicology ; 241(1-2): 92-7, 2007 Nov 20.
Article in English | MEDLINE | ID: mdl-17888559

ABSTRACT

To clarify the presence of cross-talk between H(2)S and NO, we investigated effect of NaHS, an H(2)S donor, on activity of recombinant NO synthase (NOS) isoforms. Activity of all nNOS, iNOS and eNOS was inhibited by NaHS (IC(50): 0.13-0.21 mM). In contrast, Na(2)SO(3), L-cysteine and threo-1,4-dimercapto-2,3-butanediol, a reductant, exerted poor inhibition of NOS activity. Increasing concentrations of tetrahydrobiopterin (BH(4)) reversed the NaHS inhibition of nNOS and eNOS, but not iNOS. Our data thus demonstrate inhibition of three NOS isoforms by NaHS/H(2)S, and suggest involvement of interaction of NaHS/H(2)S with BH(4) in inhibition of nNOS and eNOS, but not iNOS.


Subject(s)
Air Pollutants/toxicity , Enzyme Inhibitors , Hydrogen Sulfide/toxicity , Nitric Oxide Synthase Type III/antagonists & inhibitors , Nitric Oxide Synthase Type II/antagonists & inhibitors , Nitric Oxide Synthase Type I/antagonists & inhibitors , Biopterins/analogs & derivatives , Biopterins/metabolism , Cysteine/toxicity , Dithiothreitol/toxicity , Humans , NADP/metabolism , Recombinant Proteins , Sulfates/toxicity
8.
J Pharmacol Sci ; 104(4): 392-6, 2007 Aug.
Article in English | MEDLINE | ID: mdl-17675793

ABSTRACT

We investigated the effects of NaHS, a hydrogen sulfide (H(2)S) donor, on the tension of isolated mouse and guinea-pig bronchial rings. NaHS at 0.01 - 10 mM had no effect on the tone of those preparations without precontraction. When the preparation was precontracted with carbachol, NaHS at 0.1 - 3 mM strongly relaxed the mouse rings, but produced only slight relaxation in the guinea-pig rings. The NaHS-induced relaxation in the mouse bronchus was resistant to inhibitors of ATP-sensitive K(+) channels, soluble guanylyl cyclase, cyclooxygenase (COX)-1 or COX-2, and antagonists of tachykinin receptors. Thus, NaHS evokes bronchodilation in mice, suggesting a possible role for H(2)S in the respiratory system.


Subject(s)
Bronchi/drug effects , Bronchodilator Agents/pharmacology , Hydrogen Sulfide/pharmacology , Muscle, Smooth/drug effects , Animals , Bronchi/physiology , Bronchodilator Agents/administration & dosage , Bronchodilator Agents/metabolism , Cyclooxygenase 2 Inhibitors/pharmacology , Cyclooxygenase Inhibitors/pharmacology , Dose-Response Relationship, Drug , Guanylate Cyclase/antagonists & inhibitors , Guinea Pigs , Hydrogen Sulfide/administration & dosage , Hydrogen Sulfide/metabolism , Male , Mice , Muscle Relaxation/drug effects , Muscle, Smooth/metabolism , Potassium Channel Blockers/pharmacology , Receptors, Tachykinin/antagonists & inhibitors , Species Specificity
9.
Toxicology ; 232(1-2): 138-46, 2007 Mar 22.
Article in English | MEDLINE | ID: mdl-17276573

ABSTRACT

We characterized actions of hydrogen sulfide (H(2)S) on tension of isolated rat and mouse aortae, and then examined if H(2)S could directly modulate activity of endothelial nitric oxide (NO) synthase (eNOS). Isometric tension was recorded in rat and mouse aortic rings. Activity of recombinant bovine eNOS was determined as conversion of [(3)H]-arginine into [(3)H]-citrulline. NaHS, a H(2)S donor, caused contraction at low concentrations and relaxation at high concentrations in both rat and mouse aortae precontracted with phenylephrine. The contractile and relaxant effects of NaHS were enhanced and partially blocked, respectively, by the K(+)(ATP) channel inhibitor glibenclamide in the rat, but not mouse, aortae. In the KCl-precontracted rat aorta, NaHS produced glibenclamide-resistant contraction and relaxation. NaHS produced only relaxation, but not contraction, in the endothelium-denuded aortae, and also in the endothelium-intact aortae in the presence of inhibitors of NOS or soluble guanylate cyclase. NaHS pretreatment greatly attenuated the relaxation induced by acetylcholine, but not by an NO donor, in the tissues. Finally, we found that NaHS inhibited the conversion of [(3)H]-arginine into [(3)H]-citrulline by recombinant eNOS. NaHS thus causes contraction and relaxation in rat and mouse aortae. K(+)(ATP) channels are considered to contribute only partially to the NaHS-evoked relaxation. Most interestingly, our data demonstrate direct inhibition of eNOS by NaHS, probably responsible for its contractile activity, being evidence for a novel function of H(2)S.


Subject(s)
Air Pollutants/pharmacology , Aorta/drug effects , Hydrogen Sulfide/pharmacology , Muscle Contraction/drug effects , Nitric Oxide Synthase Type III/antagonists & inhibitors , Acetylcholine/pharmacology , Animals , Aorta/enzymology , Enzyme Inhibitors/pharmacology , Glyburide/pharmacology , Guanylate Cyclase/antagonists & inhibitors , In Vitro Techniques , Male , Mice , NG-Nitroarginine Methyl Ester/pharmacology , Nitric Oxide Synthase Type III/metabolism , Potassium Channel Blockers/pharmacology , Rats , Rats, Wistar
10.
Ann N Y Acad Sci ; 1091: 445-59, 2006 Dec.
Article in English | MEDLINE | ID: mdl-17341635

ABSTRACT

Proteinase-activated receptor-1 (PAR1), a G protein-coupled receptor (GPCR) for thrombin, can be activated not only by PAR1-activating peptides (PAR1APs) based on the N-terminal cryptic tethered ligand sequence but also by an N-palmitoylated (Pal) peptide, Pal-RCLSSSAVANRSKKSRALF-amide (P1pal-19), based on the intracellular loop 3 of PAR1, designated pepducin, in human platelets or PAR1-transfected cells. The present article evaluated the actions of P1pal-19 and also the shorter peptide, Pal-RCLSSSAVANRS-amide (P1pal-12), known as a possible PAR1 antagonist, in multiple cells/tissues that naturally express PAR1. P1pal-19 as well as a PAR1AP, TFLLR-amide, evoked cytosolic Ca(2+) mobilization in cultured human lung epithelial cells (A549) and rat gastric mucosal epithelial cells (RGM1). P1pal-19 and TFLLR-amide, but not a PAR2-activating peptide, SLIGRL-amide, caused delayed prostaglandin E(2) formation in RGM1 cells. P1pal-19, like TFLLR-amide, produced endothelial NO-dependent relaxation in rat aorta and epithelial prostanoid-dependent relaxation in mouse bronchus. The P1pal-19-induced relaxation remained constant even after desensitization of PAR1 with TFLLR-amide in either tissue. P1pal-19 failed to mimic the contractile effects of TFLLR-amide in the endothelium-denuded preparations of rat aorta or superior mesenteric artery and the rat gastric longitudinal smooth muscle strips. P1pal-12 partially inhibited the vasorelaxation caused by TFLLR-amide and P1pal-19, but not SLIGRL-amide, in the rat aorta. Our data thus indicate that P1pal-19 is capable of mimicking the effects of PAR1APs in the endothelial and epithelial, but not smooth muscle, cells/tissues, and suggest that P1pal-12 may act as a PAR1 antagonist in the vascular endothelium.


Subject(s)
Biomimetics , Intracellular Fluid/metabolism , Peptide Fragments/metabolism , Peptides/metabolism , Receptor, PAR-1/physiology , Amino Acid Sequence , Animals , Cell Line , Cell Line, Tumor , Humans , Intracellular Fluid/chemistry , Ligands , Male , Mice , Molecular Sequence Data , Muscle Relaxation/physiology , Protein Binding/physiology , Rats , Rats, Wistar , Receptor, PAR-1/antagonists & inhibitors , Receptor, PAR-1/metabolism
11.
J Pharmacol Exp Ther ; 315(2): 576-89, 2005 Nov.
Article in English | MEDLINE | ID: mdl-16120814

ABSTRACT

We investigated proteinase-activated receptor-2 (PAR(2))-triggered signal transduction pathways causing increased prostaglandin E(2) (PGE(2)) formation in human lung-derived A549 epithelial cells. The PAR(2) agonist, SLIGRL-NH(2) (Ser-Leu-Ile-Gly-Arg-Leu-amide), evoked immediate cytosolic Ca(2+) mobilization and delayed (0.5-3 h) PGE(2) formation. The PAR(2)-triggered PGE(2) formation was attenuated by inhibition of the following signal pathway enzymes: cyclooxygenases 1 and 2 (COX-1 and COX-2, respectively), cytosolic Ca(2+)-dependent phospholipase A(2) (cPLA(2)), the mitogen-activated protein kinases (MAPKs), mitogen-activated protein kinase/extracellular signal-regulated kinase kinase (MEK)-extracellular signal-regulated kinase (ERK) and p38 MAPK, Src family tyrosine kinase, epidermal growth factor (EGF) receptor tyrosine kinase (EGFRK), and protein kinase C (PKC), but not by inhibition of matrix metalloproteinases. SLIGRL-NH(2) caused prompt (5 min) and transient ERK phosphorylation, blocked in part by inhibitors of PKC and tyrosine kinases but not by an EGFRK inhibitor. SLIGRL-NH(2) also evoked a relatively delayed (15 min) and persistent (30 min) phosphorylation of p38 MAPK, blocked by inhibitors of Src and EGFRK but not by inhibitors of COX-1 or COX-2. SLIGRL-NH(2) elicited a Src inhibitor-blocked prompt (5 min) and transient phosphorylation of the EGFRK. SLIGRL-NH(2) up-regulated COX-2 protein and/or mRNA levels that were blocked by inhibition of p38 MAPK, EGFRK, Src, and COX-2 but not MEK-ERK. SLIGRL-NH(2) also caused COX-1-dependent up-regulation of microsomal PGE synthase-1 (mPGES-1). We conclude that PAR(2)-triggered PGE(2) formation in A549 cells involves a coordinated up-regulation of COX-2 and mPGES-1 involving cPLA(2), increased cytosolic Ca(2+), PKC, Src, MEK-ERK, p38 MAPK, Src-mediated EGF receptor trans-activation, and also metabolic products of both COX-1 and COX-2.


Subject(s)
Dinoprostone/biosynthesis , Epithelial Cells/metabolism , Lung/metabolism , Receptor, PAR-2/physiology , Signal Transduction/drug effects , Blotting, Western , Calcium/metabolism , Cell Line , Cell Proliferation/drug effects , Cyclooxygenase 1/biosynthesis , Cyclooxygenase 2/biosynthesis , Cytosol/drug effects , Cytosol/metabolism , Epithelial Cells/drug effects , ErbB Receptors/metabolism , Humans , Immunohistochemistry , Lung/cytology , Lung/drug effects , Microsomes/drug effects , Microsomes/enzymology , Phosphorylation , RNA, Messenger/biosynthesis , RNA, Messenger/genetics , Receptor, PAR-1/agonists , Receptor, PAR-2/agonists , Receptors, Estrogen/metabolism , Reverse Transcriptase Polymerase Chain Reaction , p38 Mitogen-Activated Protein Kinases/metabolism
12.
Life Sci ; 75(22): 2689-702, 2004 Oct 15.
Article in English | MEDLINE | ID: mdl-15369704

ABSTRACT

Receptor-activating peptides for protease-activated receptors (PARs) 1 or 2 enhance gastric mucosal blood flow (GMBF) and protect against gastric mucosal injury in rats. We thus examined and characterized the effects of PAR-1 and PAR-2 agonists on the isometric tension in isolated rat gastric artery. The agonists for PAR-2 or PAR-1 produced vasodilation in the endothelium-intact arterial rings, which was abolished by removal of the endothelium. The mechanisms underlying the PAR-2- and PAR-1-mediated relaxation involved NO, endothelium-derived hyperpolarizing factor (EDHF) and prostanoids, to distinct extent, as evaluated by use of inhibitors of NO synthase, cyclo-oxygenase and Ca2+-activated K+ channels. The EDHF-dependent relaxation responses were significantly attenuated by gap junction inhibitors. These findings demonstrate that endothelial PAR-1 and PAR-2, upon activation, dilate the gastric artery via NO and prostanoid formation and also EDHF mechanisms including gap junctions, which would enhance GMBF.


Subject(s)
Gastric Mucosa/blood supply , Receptor, PAR-1/physiology , Receptor, PAR-2/physiology , Vasodilation , Animals , Arteries/physiology , Biological Factors/physiology , Calcium/metabolism , Endothelium, Vascular/physiology , In Vitro Techniques , Male , Nitric Oxide/physiology , Rats , Rats, Wistar
13.
J Pharmacol Exp Ther ; 311(1): 402-10, 2004 Oct.
Article in English | MEDLINE | ID: mdl-15199093

ABSTRACT

We characterized the tracheal and bronchial relaxation caused by proteinase-activated receptor-2 (PAR-2) activation in ddY mice and/or in wild-type and PAR-2-knockout mice of C57BL/6 background. Ser-Leu-Ile-Gly-Arg-Leu-amide (SLIGRL-NH(2)) and Thr-Phe-Leu-Leu-Arg-amide, PAR-2- and PAR-1-activating peptides, respectively, caused relaxation in the isolated ddY mouse trachea and main bronchus. The relaxation was abolished by specific inhibitors of cyclooxygenase (COX)-1, COX-2, mitogen-activated protein kinase kinase (MEK), and p38 MAP kinase. The MEK and p38 MAP kinase inhibitors did not affect prostaglandin E(2)-induced relaxation. Inhibitors of cytosolic Ca(2+)-dependent phospholipase A(2) (PLA), Ca(2+)-independent PLA(2), diacylglycerol lipase, tyrosine kinase, and protein kinase C exhibited no or only minor inhibitory effects on the PAR-mediated relaxation. Trypsin, a PAR-2 activator, and 2-furoyl-Leu-Ile-Gly-Arg-Leu-amide, a potent PAR-2-activating peptide, in addition to SLIGRL-NH(2), caused airway relaxation in wild-type C57BL/6 mice, as in ddY mice. In PAR-2-knockout mice, the peptide effects were absent and the potency of trypsin decreased. Desensitization of PAR-2 and/or PAR-1 greatly suppressed the relaxant effect of trypsin. The bronchial and tracheal tissues displayed distinct sensitivities toward trypsin and the PAR-2-activating peptides. Our data indicate an involvement of both COX-1 and COX-2, and the MEK-extracellular signal-regulated kinase and p38 MAP kinase signaling pathways in the PAR-2- and PAR-1-triggered relaxation of mouse airway tissue, and substantiate a role for PAR-2 in regulating both the trachea and bronchial responsiveness in the mouse lung.


Subject(s)
Muscle Relaxation/physiology , Receptor, PAR-2/physiology , Animals , Cyclooxygenase 1 , Cyclooxygenase 2 , Dinoprostone/physiology , Dose-Response Relationship, Drug , Isoenzymes/metabolism , Lipoprotein Lipase/metabolism , Male , Membrane Proteins , Mice , Mice, Knockout , Mitogen-Activated Protein Kinase Kinases/metabolism , Muscle Relaxation/drug effects , Muscle, Smooth , Peptides/pharmacology , Phospholipases A/metabolism , Prostaglandin-Endoperoxide Synthases/metabolism , Receptor, PAR-1/physiology , Signal Transduction , Trachea , Trypsin/pharmacology , p38 Mitogen-Activated Protein Kinases/metabolism
14.
J Pharmacol Exp Ther ; 309(3): 1098-107, 2004 Jun.
Article in English | MEDLINE | ID: mdl-14976227

ABSTRACT

To develop potent and metabolically stable agonists for protease-activated receptor-2 (PAR-2), we prepared 2-furoylated (2f) derivatives of native PAR-2-activating peptides, 2f-LIGKV-OH, 2f-LIGRL-OH, 2f-LIGKV-NH(2), and 2f-LIGRL-NH(2), and systematically evaluated their activity in PAR-2-responsive cell lines and tissues. In both HCT-15 cells and NCTC2544 cells overexpressing PAR-2, all furoylated peptides increased cytosolic Ca(2+) levels with a greater potency than the corresponding native peptides, although a similar maximum response was recorded. The absolute potency of each peptide was greater in NCTC2544, possibly due to a higher level of receptor expression. Furthermore, the difference in potency between the 2-furoylated peptides and the native peptides was enhanced when evaluated in the rat superior mesenteric artery and further increased when measuring PAR-2-mediated salivation in ddY mice in vivo. The potency of 2f-LIGRL-NH(2), the most powerful peptide, relative to SLIGKV-OH, was about 100 in the cultured cell Ca(2+) signaling assays, 517 in the vasorelaxation assay, and 1100 in the salivation assay. Amastatin, an aminopeptidase inhibitor, augmented salivation caused by native peptides, but not furoylated peptides. The PAR-2-activating peptides, including the furoylated derivatives, also produced salivation in the wild-type C57BL/6 mice, but not the PAR-2-deficient mice. Our data thus demonstrate that substitution of the N-terminal serine with a furoyl group in native PAR-2-activating peptides dramatically enhances the agonistic activity and decreases degradation by aminopeptidase, leading to development of 2f-LIGRL-NH(2), the most potent peptide. Furthermore, the data from PAR-2-deficient mice provide ultimate evidence for involvement of PAR-2 in salivation and the selective nature of the 2-furoylated peptides.


Subject(s)
Oligopeptides/pharmacology , Receptor, PAR-2/agonists , Aminopeptidases/metabolism , Animals , Calcium Signaling/physiology , Cell Line , Endothelium, Vascular/drug effects , Endothelium, Vascular/metabolism , Female , Humans , Male , Mesenteric Arteries/drug effects , Mice , Mice, Inbred C57BL , Oligopeptides/chemistry , Oligopeptides/metabolism , Peptide Fragments/chemistry , Peptide Fragments/pharmacology , Peptides/pharmacology , Rats , Rats, Wistar , Structure-Activity Relationship , Tumor Cells, Cultured , Vasoconstriction/drug effects , Vasodilation/drug effects
15.
Cardiovasc Res ; 61(4): 683-92, 2004 Mar 01.
Article in English | MEDLINE | ID: mdl-14985065

ABSTRACT

OBJECTIVE: Protease-activated receptors (PARs) 1 and 2 are expressed in various blood vessels including rat aorta, modulating vascular tone. We investigated the roles of PAR-1 and PAR-2 in vasomotor modulation in rat superior mesenteric artery. METHODS AND RESULTS: Effects of the PAR-2-activating peptide Ser-Leu-Ile-Gly-Arg-Leu-amide (SLIGRL-amide) and the PAR-1-activating peptide Thr-Phe-Leu-Leu-Arg-amide (TFLLR-amide) on isometric tension were examined in isolated rat superior mesenteric artery or aorta. Both SLIGRL-amide and TFLLR-amide caused relaxation in the precontracted rat aortic rings. The latter peptide, but not the former, produced contraction in the resting rings. NG-nitro-L-arginine methyl ester (L-NAME), but not apamin/charybdotoxin known to block the endothelium-derived hyperpolarizing factor (EDHF) pathway, abolished the relaxation and facilitated the contraction. In the precontracted rat superior mesenteric artery, SLIGRL-amide, but not TFLLR-amide, elicited endothelium-dependent relaxation, which was only partially inhibited by L-NAME with and without indomethacin. The residual relaxation was abolished by apamin/charybdotoxin. Carbenoxolone, a gap junction inhibitor, significantly attenuated the SLIGRL-amide-evoked, EDHF-dependent relaxation, although neither 17-octadecynoic acid, a P450 epoxygenase inhibitor, nor catalase, a hydrogen peroxide scavenger, revealed inhibitory effects. The residual response resistant to carbenoxolone was unaffected by ouabain/BaCl2. In the resting artery, TFLLR-amide, but not SLIGRL-amide, produced only slight contraction, which was dramatically facilitated by combination of L-NAME and apamin/charybdotoxin or by removal of the endothelium. CONCLUSIONS: Our data suggest that, in rat superior mesenteric artery, endothelial PAR-2, upon activation, causes relaxation via both NO and EDHF pathways, and that activation of muscular PAR-1 exhibits potential contractile activity that is largely masked by NO and EDHFs pathways triggered by endothelial PAR-1. Gap junctions might be involved in the EDHF mechanisms in this artery.


Subject(s)
Mesenteric Artery, Superior/drug effects , Oligopeptides/pharmacology , Receptor, PAR-1/physiology , Receptor, PAR-2/physiology , Vasodilation/drug effects , Animals , Anti-Inflammatory Agents/pharmacology , Aorta/drug effects , In Vitro Techniques , Indomethacin/pharmacology , Male , NG-Nitroarginine Methyl Ester/pharmacology , Nitric Oxide Synthase/antagonists & inhibitors , Rats , Rats, Wistar , Trypsin/pharmacology
16.
Gastroenterology ; 126(1): 208-19, 2004 Jan.
Article in English | MEDLINE | ID: mdl-14699501

ABSTRACT

BACKGROUND AND AIMS: On activation, protease-activated receptor (PAR)-2 modulates multiple gastric functions and exerts mucosal protection via activation of sensory neurons. The role of PAR-1, a thrombin receptor, in the stomach remains unknown. We thus examined if the PAR-1 agonist could protect against gastric mucosal injury in rats. METHODS: Gastric mucosal injury was created by oral administration of ethanol/HCl or absolute ethanol in conscious rats. Gastric mucosal blood flow and acid secretion were determined in anesthetized rats. Immunohistochemical analyses of PAR-1 and cyclooxygenase (COX)-1 were also performed in rat and human stomach. RESULTS: The PAR-1 agonist TFLLR-NH(2), administered intravenously in combination with amastatin, protected against the gastric mucosal injury induced by ethanol/HCl or absolute ethanol. The protective effect of TFLLR-NH(2) was abolished by indomethacin or a COX-1 inhibitor but not by ablation of sensory neurons with capsaicin. TFLLR-NH(2) produced an NO-independent increase in gastric mucosal blood flow that was partially inhibited by blockade of the endothelium-derived hyperpolarizing factor pathway. This inhibitory effect was promoted by indomethacin. TFLLR-NH(2) suppressed carbachol-evoked acid secretion in an indomethacin-reversible manner. Immunoreactive PAR-1 and COX-1 were expressed abundantly in rat gastric muscularis mucosae and smooth muscle, and the former protein was also detectable in blood vessels. Similar staining was observed in human gastric muscularis mucosae. CONCLUSIONS: The PAR-1 agonist, given systemically, protects against gastric mucosal injury via COX-1-dependent formation of prostanoids, modulating multiple gastric functions. Our data identify a novel protective role for PAR-1 in gastric mucosa, and the underlying mechanism is entirely different from that for PAR-2.


Subject(s)
Gastric Mucosa/physiology , Receptor, PAR-1/physiology , Animals , Carbachol/pharmacology , Cyclooxygenase 1 , Cytoprotection , Ethanol , Gastric Acid/metabolism , Gastric Mucosa/drug effects , Gastric Mucosa/metabolism , Gastrointestinal Motility/drug effects , Humans , Hydrochloric Acid , Immunohistochemistry , Injections, Intravenous , Isoenzymes/metabolism , Male , Membrane Proteins , Middle Aged , Oligopeptides/administration & dosage , Oligopeptides/pharmacology , Prostaglandin-Endoperoxide Synthases/metabolism , Rats , Rats, Wistar , Receptor, PAR-1/metabolism , Stomach/drug effects , Stomach/pathology , Stomach Diseases/chemically induced , Stomach Diseases/pathology , Tissue Distribution
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