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Biomedical subjects

M Yamaya

Publications and source records attributed to M Yamaya.

At least 73 records · Page 4Linked to original sources
PubMed1996

Culture and characterization of human nasal gland cells.

To study the regulation of ion transport by human nasal gland (HNG) cells, we developed a system for culturing HNG cells isolated by enzymatic digestion from human nasal polyps. When plated on flasks in media containing. Ultroser G serum substitute and a variety of growth factors, the HNG cells became confluent after 5-7 days. Cells were collected by trypsinization and replated at 10(6) cells/cm2 on porous filters. Confluent monolayers formed on days 3-5 after replating and were studied on days 5-7. Transepithelial resistance and short-circuit current (Isc) were 177 +/- 15 omega.cm2 and 12.2 +/- 1.3 microA/cm2 (means +/- SE, n = 35). Acetylcholine (ACh, 10(-5) M) induced a transient increase in Isc by 4.4 +/- 1.0 microA/cm2 when added to both apical and basolateral sides and returned to baseline levels within 5 min. Diphenylamine-2-carboxylate (10(-3) M) decreased baseline Isc by 30.2 +/- 1.7% (n = 6) and inhibited Isc responses induced by ACh. Amiloride also decreased baseline Isc by 12.3 +/- 3.4% (n = 6) but failed to inhibit ACh-induced Isc responses. ACh (10(-5) M) also induced an increase in intracellular Ca2+ concentration measured by fura 2-AM from 60.5 +/- 16.3 to 248.3 +/- 45.3 nM (n = 4). These findings suggest that gland cells from human nasal polyps can be grown in culture to produce epithelial cell sheets of high resistance, which secrete Cl- in response to cholinergic agent via an increase in intracellular Ca2+ concentration.

Adolescent↗
PubMed1996

Role of Leukotriene-degrading enzymes in pulmonary response to antigen infusion in sensitized guinea pigs in vivo.

To determine the role of leukotriene (LT)-degrading enzymes in allergic reactions, we studied the effects of inhibitors of gamma-glutamyl transpeptidase (gamma-GTP) and dipeptidases on increases in pulmonary insufflation pressure (PIP) and vascular permeability induced by ovalbumin (OA) antigen in guinea pigs sensitized to OA antigen in vivo. Vascular permeability was assessed by the amount of extravasated Evans blue dye from the trachea, main bronchi, and segmental bronchi. An intravenous (i.v.) administration of OA antigen (200 micrograms/kg) caused increases in PIP and extravasated Evans blue dye, and OA antigen-induced effects were potentiated by gamma-GTP inhibitor L-serine borate (3 x 10(-5) M/kg, i.v.) (P < 0.05) and an inhibitor of dipeptidases, L-cysteine (3 x 10(-5) M/kg, i.v.) (P < 0.01). OA antigen-induced increases in PIP and Evans blue dye extravasation were in part inhibited by LT-receptor antagonist ONO-1078 (10(-4) M/kg, i.v.). Guinea-pig tracheal tissues contained gamma-GTP and microsomal dipeptidase activities. Histochemical and immunohistochemical studies indicate that gamma-GTP-like activity existed in the epithelium and smooth muscle, and an activity of microsomal dipeptidase was observed in the endothelial cells of microvessels and epithelium. These results suggest that LT-degrading enzymes have an important role in regulating allergic reaction in the airway in vivo.

Animals↗
PubMed1996

[Rhinovirus infection and expression of adhesion molecules in human tracheal epithelium].

Rhinovirus infection has attracted attention because it can lead to acute exacerbations of chronic inflammatory airway diseases such as bronchial asthma and chronic bronchitis. We established a culture system and inoculated human rhinovirus to human tracheal epithelial cells, and found that infection was augmented by up-regulation of intercellular adhesion molecule-1, which is the receptor for this virus. We also found that human airway epithelial cells infected with rhinovirus were susceptible to a chemical oxidant (H2O2) released by inflammatory cells, which would contribute to acute exacerbations of inflammatory airway diseases. Finally, we found that anti-ICAM-1 antibodies or dexamethasone can inhibit the infectivity to rhinovirus by suppressing ICAM-1, and diminish susceptibility to oxidants in the cultured human tracheal epithelium.

Anti-Inflammatory Agents↗
PubMed1995

The role of carbon monoxide in lucigenin-dependent chemiluminescence of rat alveolar macrophages.

We have investigated the role of carbon monoxide (CO) in lucigenin-dependent chemiluminescence of alveolar macrophages from rat lungs. CO (10 nM to 1 microM) decreased chemiluminescence of alveolar macrophages in a concentration-dependent fashion. At a concentration of 1 microM, CO significantly increased intracellular cyclic GMP levels from a control value of 175 +/- 25 fmol/2 x 10(6) cells to 431 +/- 49 fmol/2 x 10(6) cells. Pretreatment of alveolar macrophages with NG-monomethyl-L-arginine (100 microM) failed to inhibit CO (1 microM)-induced decreases in chemiluminescence of alveolar macrophages (3.7 +/- 0.7 cpm x 10(3) in the presence of NG-monomethyl-L-arginine and 3.4 +/- 0.6 cpm x 10(3) in the absence of NG-monomethyl-L-arginine) and CO (1 microM)-induced increases in intracellular cyclic GMP levels (452 +/- 65 fmol/2 x 10(6) cells in the presence of NG-monomethyl-L-arginine and 419 +/- 58 fmol/2 x 10(6) cells in the absence of NG-monomethyl-L-arginine). Decreases in chemiluminescence of alveolar macrophages induced by CO (1 microM) were concentration-dependently inhibited by methylene blue (from 0.1 microM to 10 microM). Dibutyryl cyclic GMP (db cyclic GMP) (1 mM) also reduced chemiluminescence of alveolar macrophages (1.5 +/- 0.3 cpm x 10(3) in the presence of db cyclic GMP and 3.6 +/- 0.6 cpm x 10(3) in the absence of db cyclic GMP). In contrast to CO and db cyclic GMP, zinc protoporphyrin-9 (10nM to microM), an inhibitor of heme oxygenase potentiated chemiluminescence of alveolar macrophages in a concentration-dependent fashion.(ABSTRACT TRUNCATED AT 250 WORDS)

Acridines↗
PubMed1995

Isoproterenol augments ATP-evoked Cl- secretion across canine tracheal epithelium.

Using an Ussing chamber, both the posterior epithelial membrane and cultured epithelial cell monolayers from canine trachea were used for measurements of potential difference (PD) and short circuit current (SCC). Conductance (G) was calculated as the ratio SCC/PD. Adenosine (10(-5) to 10(-3) M) failed to produce any significant increases in PD and SCC. ATP (10(-6) to 10(-4) M) produced a significant transient increase in SCC in a dose-dependent fashion, reaching a peak value within 3 min after stimulation. Isoproterenol (ISOP) at 10(-8) M itself did not significantly alter the SCC value. In both the epithelial membrane and cultured epithelial cells treated with amiloride, however, pretreatment with 10(-8) M ISOP significantly augmented the ATP-induced SCC rise, whereas G did not significantly change. These findings indicate that beta-adrenergic stimulation augments Cl- secretion induced by P2-receptor stimulation in airway epithelial cells.

Action Potentials↗
PubMed1995

Cytoplasmic motility reflects phagocytic activity in alveolar macrophages from dog lungs.

To determine whether cytoplasmic motility relates to phagocytic activity of alveolar macrophages (AM), we measured the remanent field strength (RFS) from the AM containing Fe3O4 particles (5 x 10(6) cells) and the number of phagocytized fluorescent latex spheres in the AM without having Fe3O4 particles (10(6) cells) harvested by broncho-alveolar lavage from dog lungs in vitro. Cytoplasmic motility was estimated from the relaxation rate (lambda o; min-1) calculated from the decay curve of RFS and the number of phagocytized latex spheres was counted using fluorescent microscopy after the addition of latex spheres (5 x 10(7)). The tumor necrosis factor increased both lambda o and the number of phagocytized latex spheres, and cytochalasin D and colchicine decreased them in a concentration-dependent fashion. Increases and decreases in lambda o induced by drugs paralleled the number of phagocytized latex spheres. These results suggest that cytoplasmic motility reflects phagocytic activity of AM and both cytoplasmic movement and phagocytosis may be regulated by a similar mechanism in the cytoskeletal system.

Animals↗
PubMed1995

Oxidants affect permeability and repair of the cultured human tracheal epithelium.

To examine the effects of oxidants on the airway epithelial barrier functions, human tracheal epithelial cells were cultured on porous filter membrane. Glucose oxidase (GO; 10 U/ml), hydrogen peroxide (H2O2; 4 x 10(-3) M), and xanthine (5 x 10(-4) M) plus xanthine oxidase (20 mU/ml) (X-XO) significantly increased electrical conductance across epithelial membrane (G), short-circuit current (Isc) measured with Ussing's chamber methods, and [3H]mannitol flux through the cultured epithelium. Increases in G and Isc induced by oxidants were significantly inhibited by catalase (1,000 U/ml) and the protein kinase C inhibitor staurosporine (10(-7) M), but superoxide dismutase (SOD; 100 U/ml) was without effect. GO, H2O2, and X-XO inhibited the epithelial cell growth, [3H]thymidine incorporation by the cells, and epithelial repair of artificially produced focal epithelial defects (1-2 mm diam) on plastic vessels. Catalase also inhibited effects induced by oxidants on cell growth and proliferation. These results suggest that oxidants reduce tracheal epithelial barrier functions by damaging tight junctions and inhibiting cell proliferation, and these effects of oxidants on epithelial cells may be mediated by H2O2 rather than superoxide anion and by activation of protein kinase C.

Catalase↗
PubMed1995

Viral respiratory infection increases alveolar macrophage cytoplasmic motility in rats: role of NO.

Ingested ferrimagnetic (Fe3O4) particles were used to estimate noninvasively the motion of organelles in alveolar macrophages (AM) in intact rats during viral respiratory infection by parainfluenza type 1 (Sendai) virus. Four days after instillation of Fe3O4 particles (3 mg/kg) into the lung, remnant field strength (RFS) was measured at the body surface immediately after magnetization of Fe3O4 particles by an externally applied magnetic field. RFS decreases with time, due to particle rotation (relaxation) which is related to cytoplasmic motility of AM. Viral infection increased the relaxation rate (lambda o per min), and increases in lambda o reached a maximum 3 days after nasal inoculation (day 3). Viral infection (day 3)-induced increases in lambda o were dose dependently inhibited by either the L-arginine analogue N-nitro-L-arginine or by methylene blue, an inhibitor of guanylate cyclase activity. Bronchoalveolar lavage fluid obtained from infected rats contained significantly higher levels of nitrite than that from control rats (P < 0.01). In in vitro experiments, AM from infected rats showed significantly higher lambda o, nitrite production, and intracellular guanosine 3',5'-cyclic monophosphate levels than those from control rats (P < 0.01). Sodium nitroprusside, known to release nitric oxide concentration dependently, increased lambda o of AM from noninfected rats in vitro. These results suggest that nitric oxide plays an important role in AM cytoplasmic motility during viral respiratory infection.

Animals↗
PubMed1995

Epithelial modulation of leukotriene-C4-induced human tracheal smooth muscle contraction.

We investigated the role of epithelium in smooth muscle contraction induced by leukotriene C4 (LTC4) in isolated human trachea. The contractile response to LTC4 was potentiated by a gamma-glutamyl transpeptidase (gamma-GTP) inhibitor L-serine borate and by removal of the epithelium. Both L-serine borate (4.5 x 10(-2) M) and removal of the epithelium shifted the concentration-response curves to LTC4 to lower concentrations by 1.2 and 1.0 log units, respectively. Incubation of cultured human tracheal epithelial cells with either LTC4 or LTD4 resulted in the formation of LTD4 or LTE4. The isolated epithelial cells and cultured epithelial cells contained gamma-GTP activity. Histochemical study indicated that gamma-GTP-like activity was present in the epithelial, submucosal, and smooth muscle layers. These findings suggest that the epithelium modulates the contractile response to LTC4 in human trachea by LT-degrading enzymes.

Aged↗
PubMed1995

Eosinophil penetration through cultured human airway epithelial cell layer.

We investigated the mechanisms of eosinophil penetration and mannitol permeability through a multilayer of cultured human tracheal epithelial cells. Wells of tissue culture plates were separated into the upper and the lower chambers by the cultured epithelial cell layer. 51Cr-labeled eosinophils or 3H-mannitol were put into the lower chamber. To stimulate the epithelial cells, platelet-activating factor (PAF) and/or phorbol myristate acetate (PMA) were added to the upper chamber. After 4 h of incubation, the eosinophil penetration rate was determined as a percentage of the total count added to the lower chamber. PMA significantly increased the eosinophil penetration rate in a dose-dependent manner (4.0% at 10(-5) M), compared with control (0.67%), whereas PAF itself did not. Activation of eosinophils by the addition of PAF to the lower chamber produced a significant increase in the eosinophil penetration (6.5% at 10(-6) M), which was inhibited by staurosporine. For determining the mannitol permeability, PMA, PAF, and/or supernatant from eosinophils were added to both upper and lower chambers and incubated for 30 min. PMA induced a significant increase in the mannitol permeability (175% of controls at 10(-5) M), whereas PAF itself did not alter it. Supernatant from eosinophils activated by PAF (10(-6) M) significantly increased the permeability (451% of controls), which was blocked by staurosporine. Supernatants from AA861 (a 5-lipoxygenase inhibitor)-treated or phenidon (a phospholipase A2 inhibitor)-treated eosinophils activated by PAF failed to alter the supernatant-induced increases in mannitol permeability.(ABSTRACT TRUNCATED AT 250 WORDS)

Alkaloids↗
PubMed1994

Bronchomotor agents and hysteresis of collateral resistance in dog lobe.

The effect of smooth muscle tone on hysteresis of collateral channels was examined and compared with that of airways, in freshly excised dog lobes. A double lumen catheter was sealed into a branch off the main bronchus, and air (Vs) flowed through the outer lumen while the pressure in the segment (Ps) was measured by the inner lumen. Collateral conductance (Gcoll) was calculated as Gcoll = Vs/Ps. In another series of experiments a pleural capsule was used to measure either segmental airway flow (Vsaw) or capsule pressure (Pcap). Segmental airway conductance (Gsaw) was calculated as Gsaw = Vsaw/(Ps-Pcap). Hysteresis for Gcoll vs lung volume (VL) curves were almost absent in control and after isoproterenol inflation Gcoll was greater than deflation Gcoll at a given VL (clockwise history). Conversely, after histamine Gcoll vs VL curves showed a counterclockwise history. The behaviors of Gcoll and Gsaw against a bronchomotor agent were similar. We conclude that major collateral channels have muscular walls, and being that of an airway type.

Airway Resistance↗
PubMed1994

[Advances in culture techniques for airway epithelial cells].

Techniques for culturing the airway epithelium have been improved over the past 10 years. Cultured cells show multilayered structures, and the luminal surface contains cilia and secretory granules. The cells retain the ion transport properties of the original tissue, and secrete mucin-like glycoproteins indistinguishable from mucins produced in vivo. The culture conditions were improved in several ways. A serum-free hormone-supplemented culture medium, growth supports such as collagen or collagen gel, and filter membranes or culture dishes suitable for epithelial cell culture are now used, and air interface methods have been developed. Furthermore, protease can be used to harvest many cells from the airway epithelium. This paper introduces the history of the culture techniques for the airway epithelium over the past 10 years, and recent improvements in the culture conditions for human tracheal epithelium and submuiosal glands.

Animals↗
PubMed1993

Effects of beta-adrenergic receptor activation on alveolar macrophage cytoplasmic motility.

We studied the effects of fenoterol, a beta-adrenoceptor agonist, on the cytoplasmic motility of alveolar macrophages (AM) from dog lungs in vitro. Four days after the instillation of Fe3O4 particles (3 mg/kg) into the lower lobe bronchus, AM were harvested by bronchoalveolar lavage. Remanent field strength (RFS) from the AM containing Fe3O4 particles (5 x 10(6) cells) was measured immediately after magnetization. RFS decreased with time due to particle rotation (relaxation), which is related to cytoplasmic motility of AM. Fenoterol (10(-9) M to 10(-5) M) decreased the relaxation rate (lambda 0; min-1) in a concentration-dependent fashion with the maximum effect at 10(-6) M. Both forskolin (10(-6) M to 10(-4) M) and dibutyryl adenosine 3',5'-cyclic monophosphate (cAMP) (10(-3) M) mimicked fenoterol-induced inhibitory effects on lambda 0. Fenoterol and forskolin concentration-dependently increased intracellular levels of cAMP, which were parallel to decreases in lambda 0 induced by these drugs. KT 5720 (10(-5) M), a specific inhibitor of protein kinase A, significantly inhibited fenoterol (10(-6) M)-induced inhibitory effects on lambda 0 (P < 0.01). These results imply that beta-adrenergic receptor activation inhibits cytoplasmic motility of AM via increases in intracellular levels of cAMP, which may be coupled with activation of a cAMP-dependent protein kinase.

Animals↗
PubMed1993

Calcium-dependent chloride secretion across cultures of human tracheal surface epithelium and glands.

Surface epithelium and gland cells from human trachea were cultured on porous-bottom inserts and loaded with fura 2 to permit measurement of the intracellular calcium concentration ([Ca2+]i). Short-circuit current (Isc), an index of transepithelial active ion transport, was measured on cells from the same cultures. Surface epithelial [Ca2+]i of 82 +/- 15 nM was increased transiently by isoproterenol, histamine, and bradykinin with maximal increases of 88 +/- 17, 480 +/- 149, and 978 +/- 214 nM (n = 15), respectively. Baseline [Ca2+]i in cultured gland cells of 68 +/- 11 nM was increased transiently by isoproterenol, histamine, methacholine, and bradykinin with maximal increases of 105 +/- 19, 233 +/- 47, 327 +/- 121, and 634 +/- 151 nM (n = 17-21), respectively. In both cell types, mediators that increased [Ca2+]i also increased Isc with a time course identical to the increase in [Ca2+]i. Pretreatment with the calcium chelator, 1,2-bis-(2-aminophenoxy)ethane N,N,N',N'-tetraacetic acid, acetoxymethyl ester (BAPTA-AM), had no effect on basal Isc or transepithelial resistance but markedly inhibited both the Isc and [Ca2+]i responses to agonists. Forskolin (10(-5) M), 3-isobutyl-1-methylxanthine (10(-3) M), dibutyryl adenosine 3',5'-cyclic monophosphate (10(-3) M), and 8-(4-chlorophenylthio)-cAMP (10(-3) M) had no or only trivial effects on Isc and [Ca2+]i. We suggest that mediators increase Isc across human airway epithelium by activating Ca-dependent basolateral K channels, resulting in hyperpolarization and an increased driving force for Cl exit through apical membrane Cl channels.

Calcium↗