Water Content Level in Inspired Air on Specific Airway Resistance in Rats

Respiration ◽  
1972 ◽  
Vol 29 (2) ◽  
pp. 127-134 ◽  
Author(s):  
G.N. Melville
Keyword(s):  
Water Content ◽  
Airway Resistance ◽  
Specific Airway Resistance

Changes in specific airway resistance during prolonged breathing of moist air

1970 ◽  
Vol 48 (9) ◽  
pp. 592-597 ◽  
Author(s):  
G. Norris Melville ◽  
W. T. Josenhans ◽  
W. T. Ulmer
Keyword(s):  
Relative Humidity ◽  
Water Content ◽  
Water Loss ◽  
Healthy Subjects ◽  
Airway Resistance ◽  
Tap Water ◽  
Distilled Water ◽  
Moist Air ◽  
Specific Airway Resistance ◽  
Water Elimination

Effects of increased water content of inspired air at 21–38 °C on specific airway resistance (sRaw) in 107 healthy subjects were measured with a body plethysmograph. Mean sRaw increased insignificantly at 23 °C with 92% relative humidity (water content, 20.7 g∙m−3) for up to 71 h but became significant at 6 h with water content 25 g∙m−3. Increases were greater when evaporated tap water was inhaled than when distilled water was used. It is postulated that the increase in sRaw is due to mucosal swelling and to contaminants in tap water. A theory of respiratory "water elimination" is proposed to replace the concept of respiratory water loss.

Effect of exercise, hyperpnea, and bronchoconstriction on plasma atrial natriuretic peptide

1989 ◽  
Vol 67 (6) ◽  
pp. 2565-2570 ◽  
Author(s):  
I. Rubinstein ◽  
T. F. Reiss ◽  
D. G. Gardner ◽  
J. Liu ◽  
B. G. Bigby ◽  
...  
Keyword(s):  
Atrial Natriuretic Peptide ◽  
Natriuretic Peptide ◽  
Airway Resistance ◽  
Peak Plasma ◽  
Minute Ventilation ◽  
Significant Rise ◽  
Strenuous Exercise ◽  
Base Line ◽  
Specific Airway Resistance ◽  
Atrial Natriuretic

To examine whether endogenous secretion of atrial natriuretic peptide (ANP) modifies the bronchomotor response to moderately strenuous exercise and, conversely, whether hyperpnea of exercise or bronchoconstriction alone modulates the release of ANP, we compared the rise in specific airway resistance and the rise in circulating immunoreactive ANP (IR-ANP) induced by a 5-min submaximal exercise and by eucapnic hyperpnea with cold dry air and exercise-matched minute ventilation in six healthy individuals and in five subjects with clinically stable asthma. As expected, the increase in specific airway resistance from base line provoked by exercise was greater in the asthmatic subjects (from 11.8 +/- 7.1 to 34.0 +/- 18.6 l.cmH2O.l-1.s-1) than in the healthy subjects (from 3.7 +/- 1.2 to 4.5 +/- 1.9 l.cmH2O.l-1.s-1). In both groups, exercise was associated with a similar and significant rise in plasma IR-ANP levels, ranging from 222 to 550% from base-line value in the healthy group and from 176 to 1,120% from base-line value in the asthmatic group. Peak plasma IR-ANP levels occurred from 3 to 15 min after completion of exercise with a return to base-line values within 60 min. Although eucapnic hyperpnea was associated with a similar increase in specific airway resistance as was exercise, it provoked an increase in circulating IR-ANP in only one subject.(ABSTRACT TRUNCATED AT 250 WORDS)

Capsaicin challenge, reflex bronchoconstriction, and local action of substance P

1988 ◽  
Vol 254 (5) ◽  
pp. R845-R852 ◽  
Author(s):  
D. R. Bergren
Keyword(s):  
Substance P ◽  
Guinea Pigs ◽  
Airway Resistance ◽  
Intraperitoneal Administration ◽  
Whole Body ◽  
Specific Airway Resistance ◽  
Insufflation Pressure ◽  
Substance P Receptor ◽  
Bilateral Vagotomy ◽  
Substance P Release

Capsaicin was administered as an aerosol to unanesthetized guinea pigs in a whole body plethysmograph and intravenously to anesthetized guinea pigs to investigate its mechanism of action. Capsaicin increased specific airway resistance in the unanesthetized guinea pigs and increased insufflation pressure in anesthetized guinea pigs. To investigate the possible reflex action of capsaicin, an atropine or lidocaine aerosol was administered before the capsaicin aerosol challenge in unanesthetized guinea pigs. Both lidocaine and atropine reduced the effect of capsaicin. However, neither intravenous atropine nor bilateral vagotomy antagonized the effect of injected capsaicin in the anesthetized guinea pigs. To investigate further the possible action of capsaicin, spantide (a substance P receptor antagonist) was administered before capsaicin challenge. Spantide injection in anesthetized guinea pigs attenuated the effects of the intravenous capsaicin challenge. In unanesthetized guinea pigs spantide pretreatment, as an aerosol, did not ameliorate the effects of a capsaicin aerosol challenge. However, intraperitoneal administration of spantide did reduce the effect of the capsaicin aerosol challenge as the specific airway resistance increased. Therefore, capsaicin produced its effects independent of vagal reflexes, although reflex actions of capsaicin could have occurred through other pathways. Reflex actions of capsaicin, however, were demonstrable only in the unanesthetized guinea pig. Because spantide attenuated the effect of capsaicin, increased insufflation pressure and specific airway resistance due to capsaicin challenge in both unanesthetized and anesthetized guinea pigs may be attributed, at least in part, to capsaicin's induction of substance P release or the release of other tachykinins.

Measurement of specific airway resistance decreased the risk of delay in asthma diagnosis in children

2009 ◽  
Vol 30 (1) ◽  
pp. 47-54 ◽  
Author(s):  
Agnieszka Brzozowska ◽  
Paweł Majak ◽  
Tomasz Grzelewski ◽  
Włodzimierz Stelmach ◽  
Joanna Kaczmarek ◽  
...  
Keyword(s):  
Airway Resistance ◽  
Asthma Diagnosis ◽  
Specific Airway Resistance

scholarly journals The effect of short-term and long-term application of fisetin on experimentally induced airway hyperreactivity

2017 ◽  
Vol 64 (1) ◽  
pp. 7-9
Author(s):  
I. Kazimierová ◽  
L. Pappová ◽  
M. Šútovská ◽  
S. Fraňová
Keyword(s):  
Airway Inflammation ◽  
Airway Resistance ◽  
Chronic Administration ◽  
Airway Hyperreactivity ◽  
Whole Body ◽  
Short Term ◽  
Specific Airway Resistance ◽  
Term Administration

AbstractBackground:Fisetin, a derivate from the flavonol group may possess a variety of pharmacological effects. The aim of the presented study was to evaluate the bronchodilatory effect of fisetin after the acute or the chronic administration to guinea pigs with allergic airway inflammation.Methods:Experimental animals were sensitized and challenged by ovalbumin. Fisetin was administered in dose 5mg/kg/p.o., either once after the end of 21-days sensitization or daily during the 21-days sensitization. By using the whole-body plethysmograph, we monitored the specific airway resistance, a parameter of airway hyperreactivityin vivo. The changes of the specific airway resistance were evaluated after the short-term inhalation of the bronchoconstriction mediator-histamine (10−6mol.1−1).Results:Our results showed that the short-term as well as the long-term administration of fisetin caused decrease of the specific airway resistance values. The bronchodilatory effect of fisetin was comparable to the long-acting beta2sympathomimetic – salmeterol after the long-term administration. The measurements of the bronchodilatory activity after single administration have revealed more prolonged effect of fisetin comparing to the short-acting beta2sympathomimetic – salbutamol, as this remained even after the 5 hours, when salbutamol was already ineffective.Conclusion:In conclusion, flavonol – fisetin has shown bronchodilatory potential. In the light of this fact, fisetin may represent potential substance that can be effective in both prevention as well as control of airway inflammation symptoms.

scholarly journals Predictors of Specific Airway Resistance during Childhood

2014 ◽  
Vol 189 (9) ◽  
pp. 1019-1021
Author(s):  
Debra A. Stern ◽  
Nipasiri Voraphani ◽  
Wayne J. Morgan
Keyword(s):  
Airway Resistance ◽  
Specific Airway Resistance

Assessment of acute bronchodilator effects from specific airway resistance changes in stable COPD patients

2014 ◽  
Vol 197 ◽  
pp. 36-45 ◽  
Author(s):  
Pierachille Santus ◽  
Dejan Radovanovic ◽  
Sonia Henchi ◽  
Fabiano Di Marco ◽  
Stefano Centanni ◽  
...  
Keyword(s):  
Airway Resistance ◽  
Specific Airway Resistance ◽  
Copd Patients
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