|
||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
 |
ABSTRACT |
|---|
TOP
ABSTRACT
INTRODUCTION
METHODS
RESULTS
DISCUSSION
REFERENCES
|
|---|
In a guinea pig model of allergic asthma, we have recently established that a deficiency of nitric oxide
(NO) contributes to the increased ex vivo responsiveness of isolated perfused tracheae to methacholine after the early asthmatic reaction at 6 h after inhalational challenge of the animals with ovalbumin aerosol. Because this deficiency could be caused by a reaction of NO with enhanced levels of inflammation-induced superoxide anion (O
2), we examined the effect of endogenous O2 on the
regulation of methacholine-induced constriction by NO of intact perfused tracheal tube preparations
from unchallenged (control) guinea pigs and from animals 6 h after ovalbumin challenge. In the
presence of the NO synthase (NOS) inhibitor N 
-nitro-L-arginine methyl ester (L-NAME; 100 µM), tracheae obtained from unchallenged guinea pigs showed a 1.7-fold increase in the maximal response
to intraluminally applied methacholine (p < 0.05). By contrast, the maximal airway response to
methacholine was significantly decreased in the presence of the O2 scavenger superoxide dismutase
(SOD; 100 U/ml), by approximately 45% (p < 0.01). The SOD-induced decrease in responsiveness to methacholine was reversed by L-NAME. Tracheal preparations obtained at 6 h after allergen challenge showed a 1.8-fold increased responsiveness to intraluminally applied methacholine compared
with controls (p < 0.001), which was not further enhanced in the presence of L-NAME. SOD had neither an effect on the increased responsiveness nor did it restore the potentiating effect of L-NAME.
These results indicate that (1) in normoreactive tracheal preparations, the regulatory role of NO is
partially counteracted by endogenous O2, and ( 2) the deficiency of NO in hyperreactive tracheae obtained at 6 h after ovalbumin challenge is not caused by its reaction with O2, but rather to decreased
cNOS activity. De Boer J, Pouw FMH, Zaagsma J, Meurs H. Effects of endogenous superoxide
anion and nitric oxide on cholinergic constriction of normal and hyperreactive guinea pig
airways.
| |
INTRODUCTION |
|---|
|
TOP
ABSTRACT
INTRODUCTION
METHODS
RESULTS
DISCUSSION
REFERENCES
|
|---|
Several lines of evidence indicate that nitric oxide (NO) is importantly involved in the regulation of airway smooth muscle tone. In vitro, stimulation of the inhibitory nonadrenergic, noncholinergic (iNANC) nerves causes relaxation of airway smooth muscle from various species, including guinea pigs and humans, which can at least partially be blocked in the presence of NO synthase (NOS) inhibitors (1). Furthermore, NO causes a concentration-dependent relaxation of guinea pig tracheal strips precontracted with carbachol (4), whereas in the presence of the NOS inhibitors L-NAME and NG-monomethyl-L-arginine (L-NMMA), muscarinic agonist and histamine-induced constriction of intact perfused guinea pig tracheal tube preparations is enhanced (5, 6). In addition, the endothelin-1 and bradykinin-induced epithelium-dependent relaxation of guinea pig trachea in vitro was shown to be mediated by NO (7, 8).
In vivo, inhaled NO reverses histamine and methacholine-induced bronchoconstriction in guinea pigs (9), dogs (10), and humans (11), whereas in the guinea pig administration of L-NAME causes enhanced bronchoconstriction in response to both allergens (12) and contractile agonists (5, 13).
Airway hyperreactivity to pharmacologic stimuli such as histamine and muscarinic agonists is a hallmark of allergic asthma. Using a guinea pig model of allergic asthma, characterized by allergen-induced early and late asthmatic reactions, airway inflammation and airway hyperreactivity to histamine and methacholine after these reactions (14, 15), we have recently demonstrated that a deficiency of NO contributes to the hyperresponsiveness of intact perfused tracheae to histamine and methacholine, as observed after the early asthmatic reaction (6).
The mechanism of the NO deficiency after the early asthmatic reaction is presently unknown. Because allergic asthma
both in guinea pigs and in humans is associated with enhanced
production of superoxide anion (O2) by a variety of inflammatory cells (16), it can be hypothesized that inactivation
of NO by increased levels of O 2 is involved. Thus, O 2, like
NO, being a radical is a potent chemical inactivator of NO by
its fast reaction with this bronchodilator to form peroxynitrite (ONOO ) (21). Evidence for an NO scavenging role of O2 in
the regulation of smooth muscle contraction has been found previously in the vasculature (22) and in the gastrointestinal (25) and urogenital (26) tract.
In the present study, we examined the effect of inactivation
of O 2 by superoxide dismutase (SOD) on the efficacy of endogenous NO in inhibiting methacholine-induced contraction
of perfused guinea pig tracheal preparations. This was performed in normoreactive airways obtained from unchallenged
control animals, as well as in hyperreactive airways from
guinea pigs obtained at 6 h after allergen provocation in order
to investigate the hypothesis that NO-scavenging by O 2 contributes to allergen-induced airway hyperresponsiveness after the early asthmatic reaction.
| |
METHODS |
|---|
|
TOP
ABSTRACT
INTRODUCTION
METHODS
RESULTS
DISCUSSION
REFERENCES
|
|---|
Animals
Outbred specific pathogen-free guinea pigs (Charles River SAVO, Kiszlegg, Germany), weighing 500 to 800 g, were used in this study. All animals were actively IgE-sensitized to ovalbumin (OA) at 3 wk of age as described by Van Amsterdam and colleagues (27). In short, 0.5 ml of an allergen solution containing 100 µg/ml ovalbumin and 100 mg/ml Al(OH)3 in saline was injected intraperitoneally, and another 0.5 ml was divided over seven intracutaneous injection sites in the proximity of lymph nodes in the paws, lumbar regions, and neck. The animals were used experimentally in Weeks 4 to 8 after sensitization. The animals were group-housed in individual cages in climated animal quarters and given water and food ad libitum while a 12-h on/12-h off light cycle was maintained.
All protocols described in this study were approved by the University of Groningen Animal Health Committee.
Allergen Provocation
Ovalbumin provocations were performed by inhalation of aerosolized solutions. The provocations were performed in a specially designed animal cage in which the guinea pigs could move freely (14). The volume of the cage was 9 L, which ensured fast replacement of the air inside the cage with aerosol and vice versa. A DeVilbiss nebulizer (type 646; DeVilbiss, Somerset, PA) driven by an airflow of 8 L/min provided the aerosol required, with an output of 0.33 ml/min.
Allergen provocations were performed by inhalation of increasing aerosol concentrations of 0.5, 1.0, 3.0, 5.0, and 7.0 mg/ml ovalbumin in saline for 3 min, separated by 10-min intervals. Allergen inhalations were discontinued when the first signs of respiratory distress were observed. No antihistaminic was needed to prevent the development of anaphylactic shock. Previous studies measuring pleural pressure changes in ovalbumin-sensitized, permanently instrumented, unrestrained guinea pigs have indicated that the allergen-induced early asthmatic reaction induced by this procedure is maximal within 20 min and lasts for as long as 5 h (14, 15).
Tracheal Perfusion
Six hours after ovalbumin challenge, the guinea pigs were killed. Nonchallenged IgE-sensitized animals were used as controls. The animals were killed by a sharp blow on the head and exsanguinated. The tracheas were rapidly removed and placed in Krebs-Henseleit (KH) solution (37° C) of the following composition (mM): NaCl, 117.50; KCl, 5.60; MgSO4, 1.18; CaCl2, 2.50; NaH2PO4, 1.28; NaHCO3, 25.00; D-glucose, 5.50 and gassed with 5% CO2/95% O2 at pH 7.4.
The tracheas were prepared free of serosal connective tissue and
cut into two halves of approximately 17 mm before mounting in a perfusion setup, as described previously (6). To this aim, the tracheal
preparations were attached at each side to stainless steel perfusion
tubes fixed in a Delrin perfusion holder. The holder with the trachea
was then placed in a water-jacketed organ bath (37° C) containing 20 ml of gassed KH (the serosal or extraluminal [EL] compartment). The
lumen was perfused with recirculating KH from a separate 20-ml bath
(mucosal or intraluminal [IL] compartment) at a constant flow rate of
12 ml/min. Two axially centered side-hole catheters connected with
pressure transducers (TC-XX;Viggo-Spectramed B.V., Bilthoven, The
Netherlands) were situated at the distal and proximal ends of the trachealis to measure hydrostatic pressures (Poutlet and Pinlet, respectively).
The signals were fed into a differential amplifier to obtain the difference between the two pressures (
P = Pinlet 
Poutlet), which was plotted on a flatbed chart recorder (BD 41; Kipp en Zonen, Delft, The
Netherlands). P reflects the resistance of the tracheal segment to
perfusion and is a function of the mean diameter of the trachea between the pressure taps (28). The transmural pressure in the trachea was set at 0 cm H2O. At the perfusion flow rate used, a baseline P of
0.1 to 1.0 cm H2O was measured, depending on the diameter of the
preparation.
After a 45-min equilibration period with three washes with fresh KH (both IL and EL), 1 µM isoproterenol was added to the EL compartment for maximal smooth muscle relaxation to assess basal tone. After three washes for at least 30 min, the trachea was exposed to EL 40 mM KCl in KH to obtain a receptor-independent reference response. Subsequently, the preparation was washed four times with KH for 45 min until basal tone was reached and a cumulative concentration response curve (CCRC) was made with IL methacholine. When used, SOD (100 U/ml, occasionally 1,000 U/ml) was applied to the IL or EL reservoir 30 min prior to agonist addition. L-NAME (100 µM) was added to the IL reservoir 45 min prior to agonist addition.
Data Analysis
To correct for differences in baseline P and in P changes in response to contractile stimuli caused by variation in resting internal diameter of the preparations used, IL responses of the tracheal tube
preparations to methacholine were expressed as a percentage of the
response induced by EL administration of 40 mM KCl. The contractile effect of 10 mM methacholine (highest concentration) was defined
as Emax. Using this Emax, the sensitivity to methacholine was evaluated as pEC50 (log EC50) value.
The results are expressed as means ± SEM. Statistical analysis was performed using Student's t test for unpaired observations. Differences were considered statistically significant at p < 0.05.
Chemicals
Histamine hydrochloride, ovalbumin (Grade III), aluminum hydroxide, ()-isoproterenol hydrochloride, superoxide dismutase (isolated
from bovine erythrocytes) and L-N-nitro arginine methyl ester
(L-NAME) were obtained from Sigma Chemical Co. (St. Louis, MO)
and methacholine chloride from Aldrich (Milwaukee, WI).
| |
RESULTS |
|---|
|
TOP
ABSTRACT
INTRODUCTION
METHODS
RESULTS
DISCUSSION
REFERENCES
|
|---|
In perfused tracheal preparations from unchallenged guinea
pigs, the NOS inhibitor L-NAME (100 µM, IL) caused a marked
1.7-fold potentiation of the Emax value of IL methacholine
(p < 0.05), without an effect on the sensitivity (pEC50) to this
agonist (Figure 1A and Table 1). By contrast, inactivation of
O2 with SOD (100 U/ml) resulted in a significant decrease in
the Emax of the tracheal preparations to IL methacholine by
approximately 45% (p < 0.01), irrespective of the route of administration of SOD (IL or EL; Figure 1B and Table 1). In addition, a small but significant decrease in sensitivity to the agonist
was observed in the presence of SOD (Table 1). Inhibition of
NOS with L-NAME reversed the SOD-induced decrease in responsiveness to IL methacholine (Figure 1C and Table 1).
|
|
In the ovalbumin-challenged group of animals, the absolute P response to KCl was unchanged compared with that in
the control group (5.93 ± 1.18 versus 6.55 ± 2.19 cm H2O, respectively, NS). However, the Emax to IL methacholine was
significantly increased by 1.8-fold (p < 0.001), without a
change in pEC50 (Figure 2A and Table 1). This increase was
not further enhanced in the presence of L-NAME (Figure 2A
and Table 1). In addition, the enhanced responsiveness to
methacholine was not reversed in the presence of both IL or
EL SOD, at a concentration of 100 U/ml (Figure 2B and Table
1). A similar result was obtained, when using a tenfold higher
concentration (1,000 U/ml, EL) of the O2 scavenger (Figure
2B). Furthermore, there was no effect of SOD on the tracheal
responsiveness to methacholine in the presence of L-NAME
(Figure 2C and Table 1). Both in the control preparations and in
preparations from the ovalbumin-challenged animals, L-NAME and SOD, as well as the combination of these agents, had no
effect on basal and KCl-induced tone (data not shown).
|
| |
DISCUSSION |
|---|
|
TOP
ABSTRACT
INTRODUCTION
METHODS
RESULTS
DISCUSSION
REFERENCES
|
|---|
Using perfused tracheal tube preparations obtained from unchallenged ovalbumin-sensitized control guinea pigs, it was
demonstrated that endogenous NO counteracts IL methacholine-induced airway narrowing and that this regulation is partially under negative control of endogenous O2. This is indic ated by the observation that the NOS inhibitor L-NAME
potentiates methacholine-induced tracheal contraction, whereas
the O2 scavenger SOD reduces the contractile agonist-induced
response, presumably by preventing the reaction of the superoxide anion with endogenous NO to form ONOO (21). Evidence for a NO-scavenging role of endogenous O2 in the regulation of smooth muscle tone was first documented in the
vasculature, where endothelium-dependent relaxations mediated by NO were potentiated in the presence of SOD (22, 23),
while these relaxations were reduced in the presence of O 2
generating systems (23), or when endogenous SOD was inhibited (24). Similar observations were done with respect to
iNANC nerve- or exogenous NO-mediated relaxation of gastrointestinal (25) and urogenital (26) smooth muscle preparations.
The role of O 2 as NO scavenger in the unchallenged airway preparations was confirmed by the observation that the
SOD-induced reduction of methacholine-induced tone was reversed by the NOS-inhibitor L-NAME. The reversal also suggests that the effect of O2 on the tracheal responsiveness to
methacholine is exerted only via inactivation of methacholine-induced NO production. The absence of a direct effect of endogenous O 2 on tracheal smooth muscle is supported by the
observation that SOD had no effect on basal tone. The observation that IL and EL SOD inhibited methacholine-induced
tracheal constriction to the same extent suggests that maximal
inactivation of O 2 was obtained under both conditions used.
As in a previous study (6), we demonstrated that tracheal preparations obtained from guinea pigs after the early asthmatic reaction at 6 h after allergen challenge had an increased responsiveness to methacholine. This finding seems to be in contrast with a number of other previous studies using human or animal isolated airway ring or strip preparations, demonstrating that (allergen-induced) airway hyperreactivity to contractile agonists in vivo is associated with a normal or even decreased reactivity of the ex vivo preparations to these agonists (for review see reference 29). However, since the perfused tracheal preparations used in the present study retained structural airway integrity, it may be concluded that allergen-induced airway hyperreactivity is mainly caused by geometric and/or epithelial changes and not by changes of airway smooth muscle function, which is the main determinant of contraction in airway strip or ring preparations. Because the observed ex vivo hyperreactivity was closely mimicked by the administration of L-NAME to control preparations of unchallenged guinea pigs, whereas, in addition, the hyperreactive airway preparations were unresponsive to the NOS-inhibitor, it can be concluded that a deficiency of contractile agonist-induced NO in the airways is a major determinant of the observed hyperreactivity. Very recently, similar results were obtained in vivo by the use of inhaled L-NAME (13).
The source of NO in our perfused control preparations is unknown. However, the NO was most likely produced by a constitutive isotype of NOS (cNOS) since only the agonist- induced constriction and not KCl-induced constriction or basal tone was increased after inhibition of NOS activity by L-NAME. cNOS in the airways is basally expressed in the neuronal, endothelial, and epithelial cells (30). Because the epithelium appears to be an important source of contractile agonist-induced NO production in the guinea pig trachea (5, 8), and allergen challenge may cause epithelial damage because of inflammation of the airways (31), we previously hypothesized that the deficiency of NO in the trachea of hyperreactive guinea pigs was due to epithelial shedding. However, no damage of the airway epithelium was observed in tracheal preparations of ovalbumin-challenged guinea pigs after the early asthmatic reaction, which makes this possibility unlikely (6).
Nevertheless, bronchoalveolar lavage studies have indicated that allergen-induced airway hyperreactivity after the
early asthmatic reaction in our guinea pig model is associated
with a marked influx of (activated) eosinophils and neutrophils in the airways (15, 32). Because these cells (16, 20, 33), as
well as alveolar macrophages (19) and the airway epithelium
(34), have the capacity to generate reactive oxygen species in
response to proinflammatory stimuli, scavenging of NO by inflammation-induced enhanced O2 production would be an alternative mechanism underlying the allergen-induced deficiency
of biologic action of this molecule and subsequent airway hyperreactivity. However, SOD, even in a concentration as great
as 1,000 U/ml, had no effect on the increased responsiveness
to methacholine in the tracheal preparations obtained at 6 h
after allergen challenge, and it did not restore the potentiating effect of L-NAME on methacholine-induced tone in these preparations either, which indicates that inactivation of NO by O2
was not involved.
Our study does not exclude the possibility that in allergic
asthma enhanced production of O 2 after allergen challenge is
involved in the development of airway hyperreactivity by other
mechanisms. Thus, reactive oxygen species in the lung may enhance the inflammatory response and airway reactivity by provoking mediator release and chemotaxis, inhibition of epithelial neutral endopeptidase activity, airway secretion and
enhanced vascular permeability (reviewed in reference 18).
Indeed, direct evidence that O2 may be involved in the allergen-induced airway hyperreactivity was recently reported by
Ikuta and colleagues (35), who showed inhibition of ovalbumin-induced airway hyperreactivity to acetylcholine by a polyoxyethylene-modified long-acting SOD in guinea pigs after repeated allergen challenge. In addition, enhanced O 2 production by polymorphonuclear leukocytes has also been implicated in the airway hyperreactivity of patients with chronic
airway obstruction (33).
In conclusion, our study demonstrated that under basal
conditions, the inhibitory effect of endogenous NO on cholinergic airway tone is under negative control of O 2. However,
enhanced O 2 production, by its reaction with NO, may not be
the cause of the deficiency of NO in hyperreactive tracheae
obtained after the allergen-induced early asthmatic reaction,
suggesting that this deficiency is due rather to a reduced cNOS
activity.
| |
Footnotes |
|---|
Correspondence and requests for reprints should be addressed to Jacob De Boer, Department of Molecular Pharmacology, University Centre for Pharmacy, Antonius Deusinglaan 1, 9713 AV Groningen, The Netherlands.
(Received in original form November 4, 1997 and in revised form June 23, 1998).
Acknowledgments: The writers thank Mrs. F. E. Schuurman and Mr. M. Duyvendak for expert technical assistance.
Supported by Glaxo-Wellcome Nederland BV.
| |
References |
|---|
|
TOP
ABSTRACT
INTRODUCTION
METHODS
RESULTS
DISCUSSION
REFERENCES
|
|---|
1. Tucker, J. F., S. R. Brave, L. Charalambous, A. J. Hobbs, and A. Gibson. 1990. L-NG-nitro arginine inhibits non-adrenergic, non-cholinergic relaxations of guinea-pig isolated tracheal smooth muscle. Br. J. Pharmacol. 100: 663-664 [Medline].
2. Belvisi, M. G., C. D. Stretton, M. Yacoub, and P. J. Barnes. 1992. Nitric oxide is the endogenous neurotransmittor of bronchodilator nerves in humans. Eur. J. Pharmacol. 210: 221-222 [Medline].
3. Ellis, J. L., and B. J. Undem. 1992. Inhibition by L-NG-nitro-L-arginine of nonadrenergic-noncholinergic-mediated relaxations of human isolated central and peripheral airways. Am. Rev. Respir. Dis. 146: 1543-1547 [Medline].
4.
Munakata, M.,
Y. Masaki,
I. Sakuma,
H. Ukita,
Y. Otsuka,
Y. Homma, and
Y. Kawakami.
1990.
Pharmacological differentiation of epithelium-derived relaxing factor from nitric oxide.
J. Appl. Physiol.
69:
665-670
5. Nijkamp, F. P., H. J. Van der Linde, and G. Folkerts. 1993. Nitric oxide synthesis inhibitors induce airway hyperresponsiveness in the guinea pig in vivo and in vitro. Am. Rev. Respir. Dis. 148: 727-734 [Medline].
6. De Boer, J., H. Meurs, W. Coers, M. Koopal, A. E. Bottone, A. C. Visser, W. Timens, and J. Zaagsma. 1996. Deficiency of nitric oxide in allergen-induced airway hyperreactivity to contractile agonists after the early asthmatic reaction: an ex vivo study. Br. J. Pharmacol. 116: 1109-1116 .
7. Filep, J. G., B. Battistini, and P. Sirois. 1993. Induction of endothelin-1 of epithelium-dependent relaxation of guinea-pig trachea in vitro: role for nitric oxide. Br. J. Pharmacol. 109: 637-644 [Medline].
8. Figini, M., F. L. M. Ricciardolo, P. Javdan, F. P. Nijkamp, C. Emanueli, P. Pradelles, G. Folkerts, and P. Gepetti. 1996. Evidence that epithelium-derived relaxing factor released by bradykinin in the guinea pig trachea is nitric oxide. Am. J. Respir. Crit. Care Med. 153: 918-923 [Abstract].
9. Dupuy, P. M., P. A. Shore, J. M. Drazen, C. Frostell, W. A. Hill, and W. M. Zapol. 1992. Bronchodilator action of inhaled nitric oxide in guinea pigs. J. Clin. Invest. 90: 421-428 .
10. Brown, R. H., E. A. Zerhouni, and C. A. Hirshman. 1994. Reversal of bronchoconstriction by inhaled nitric oxide: histamine versus methacholine. Am. J. Respir. Crit. Care Med. 150: 233-237 [Abstract].
11. Kacmarek, R. M., R. Ripple, B. A. Cockrill, K. J. Bloch, W. M. Zapol, and D. C. Johnson. 1996. Inhaled nitric oxide: a bronchodilator in mild asthmatics with methacholine-induced bronchospasm. Am. J. Respir. Crit. Care Med. 153: 128-135 [Abstract].
12. Persson, M. G., S. G. Friberg, P. Hedqvist, and L. E. Gustafsson. 1993. Endogenous nitric oxide counteracts antigen-induced bronchoconstriction. Eur. J. Pharmacol. 249: R7-R8 [Medline].
13. Schuiling, M., A. B. Zuidhof, M. A. A. Bonouvrie, N. Venema, J. Zaagsma, and H. Meurs. 1998. Role of nitric oxide in the development and partial reversal of allergen-induced airway hyperreactivity in conscious, unrestrained guinea-pigs. Br. J. Pharmacol. 123: 1450-1456 [Medline].
14. Santing, R. E., H. Meurs, Th. W. M. van der Mark, R. Remie, W. C. Oosterom, F. Brouwer, and J. Zaagsma. 1992. A novel method to assess airway function parameters in chronically instrumented, unrestrained guinea pigs. Pulm. Pharmacol. 5: 265-272 [Medline].
15. Santing, R. E., C. G. Olymulder, J. Zaagsma, and H. Meurs. 1994. Relationships among allergen-induced early and late phase airway obstructions, bronchial hyperreactivity, and inflammation in conscious, unrestrained guinea pigs. J. Allergy Clin. Immunol. 93: 1021-1030 [Medline].
16. Meltzer, S., B. Goldberg, P. Lad, and J. Easton. 1989. Superoxide generation and its modulation by adenosine in the neutrophils of subjects with asthma. J. Allergy Clin. Immunol. 83: 960-966 [Medline].
17. Sedgwick, J. B., K. M. Geiger, and W. W. Busse. 1990. Superoxide generation by hypodense eosinophils from patients with asthma. Am. Rev. Respir. Dis. 142: 120-125 [Medline].
18. Barnes, P. J.. 1990. Reactive oxygen species and airway inflammation. Free Radic. Biol. Med. 9: 235-243 [Medline].
19. Calhoun, W. J., H. E. Reed, D. R. Moest, and C. A. Stevens. 1992. Enhanced superoxide production by alveolar macrophages and air-space cells, airway inflammation, and alveolar macrophage density changes after segmental antigen bronchoprovocation in allergic subjects. Am. Rev. Respir. Dis. 145: 317-325 [Medline].
20. Cerasoli, F., J. Tocker, and W. M. Selig. 1991. Airway eosinophils from actively sensitized guinea pigs exhibit enhanced superoxide anion release in response to antigen challenge. Am. J. Respir. Cell Mol. Biol. 4: 195-201 .
21. Huie, R. E., and S. Padmaja. 1993. The reaction of NO with superoxide. Free Radic. Res. Commun. 18: 195-199 [Medline].
22. Gryglewski, R. J., R. M. J. Palmer, and S. Moncada. 1986. Superoxide anion is involved in the breakdown of endothelium-derived vascular relaxing factor. Nature 320: 454-456 [Medline].
23.
Ignarro, L. J.,
R. E. Byrns,
G. M. Buga,
K. S. Wood, and
G. Chauduri.
1987.
Pharmacological evidence that endothelium-derived relaxing
factor is nitric oxide: use of pyrogallol and superoxide dismutase to
study endothelium-dependent and nitric oxide-elicited vascular smooth
muscle relaxation.
J. Pharmacol. Exp. Ther.
244:
181-189
24. Omar, H. A., P. D. Cherry, M. P. Mortelliti, T. Burke-Wolin, and M. S. Wolin. 1991. Inhibition of coronary artery superoxide dismutase attenuates endothelium-dependent and -independent nitrovasodilator relaxation. Circ. Res. 69: 601-608 [Abstract].
25.
Chakder, S., and
S. Rattan.
1991.
Neurally mediated relaxation of opossum internal anal sphincter: influence of superoxide anion generator
and the scavanger.
J. Pharmacol. Exp. Ther.
260:
1113-1118
26. Martin, W., K. H. McAllister, and K. Paisly. 1994. NANC neurotransmission in the bovine retractor penis is blocked by superoxide anion following inhibition of superoxide dismutase with diethyldithiocarbamate. Neuropharmacology 33: 1293-1301 [Medline].
27.
Van Amsterdam, R. G. M.,
F. Brouwer, and
J. Zaagsma.
1989.
Analysis
of the 
-adrenoceptor mediated inhibition of IgG- and IgE-dependent
guinea pig anaphylactic tracheal smooth muscle contraction.
Agents
Actions
26:
48-51
[Medline].
28.
Munakata, M.,
I. Huang,
W. Mitzner, and
H. Menkes.
1989.
Protective
role of epithelium in the guinea pig airway.
J. Appl. Physiol
66:
1547-1552
29. Meurs, H., and J. Zaagsma. 1991. Pharmacological and biochemical changes in airway smooth muscle in relation to bronchial hyperresponsiveness. In D. K. Agrawal and R. G. Townley, editors. Inflammatory cells and Mediators. CRC Press, Boca Raton. 1-38.
30. Kobzik, L., D. S. Bredt, C. J. Lowenstein, J. Drazen, B. Gaston, D. Sugarbaker, and J. S. Stamler. 1993. Nitric oxide synthase in human and rat lung: immunocytochemical and histochemical localization. Am. J. Respir. Cell Mol. Biol. 9: 371-377 .
31. Laitinen, L. A., M. Heino, A. Laitinen, T. Kava, and T. Haahtela. 1985. Damage of the airway epithelium and bronchial reactivity in patients with asthma. Am. Rev. Respir. Dis. 131: 599-606 [Medline].
32. Santing, R. E., Y. Hoekstra, Y. Pasman, J. Zaagsma, and H. Meurs. 1994. The importance of eosinophil activation for the development of allergen-induced bronchial hyperreactivity in conscious, unrestrained guinea-pigs. Clin. Exp. Allergy 24: 1157-1163 [Medline].
33. Postma, D. S., T. E. J. Renkema, J. A. Noordhoek, J. Faber, H. J. Sluiter, and H. F. Kauffman. 1988. Association between nonspecific bronchial hyperreactivity and superoxide anion production by polymorphonuclear leukocytes in chronic airflow obstruction. Am. Rev. Respir. Dis. 137: 57-61 [Medline].
34.
Kinnula, V. L.,
K. B. Adler,
N. S. Ackley, and
J. D. Crapo.
1992.
Release
of reactive oxygen species by guinea pig tracheal epithelial cells in
vitro.
Am. J. Physiol.
262:
L708-L712
35. Ikuta, N., S. Sugiyama, K. Takagi, T. Satake, and T. Ozawa. 1992. Implication of oxygen radicals on airway hyperresponsiveness after ovalbumin challenge in guinea pigs. Am. Rev. Respir. Dis. 145: 561-565 [Medline].
This article has been cited by other articles:
 |
|
 |
|
  S. M. Wells and A. Holian Asymmetric Dimethylarginine Induces Oxidative and Nitrosative Stress in Murine Lung Epithelial Cells Am. J. Respir. Cell Mol. Biol., May 1, 2007; 36(5): 520 - 528. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 A. Samb, C. Taille, A. Almolki, J. Megret, J. M. Staddon, M. Aubier, and J. Boczkowski Heme oxygenase modulates oxidant-signaled airway smooth muscle contractility: role of bilirubin Am J Physiol Lung Cell Mol Physiol, September 1, 2002; 283(3): L596 - L603. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 G. Thabut, J. El-Benna, A. Samb, S. Corda, J. Megret, G. Leseche, E. Vicaut, M. Aubier, and J. Boczkowski Tumor Necrosis Factor-alpha Increases Airway Smooth Muscle Oxidants Production through a NADPH Oxidase-like System to Enhance Myosin Light Chain Phosphorylation and Contractility J. Biol. Chem., June 14, 2002; 277(25): 22814 - 22821. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 M. Aoki, S. Yamamoto, M. Kobayashi, K. Ohga, H. Kanoh, K. Miyata, K. Honda, and T. Yamada Antiasthmatic Effect of YM976, a Novel PDE4 Inhibitor, in Guinea Pigs J. Pharmacol. Exp. Ther., April 1, 2001; 297(1): 165 - 173. [Abstract] [Full Text]
|
|
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| Proc. Am. Thorac. Soc. | Am. J. Respir. Cell Mol. Biol. |