Abstract
Although a role for the bronchial circulation in clearance of bronchoactive agents has been frequently proposed, experimental evidence is limited. In this study, we determined the importance of bronchial blood flow (Q̇(BA)) in the recovery from methacholine-(MCh) induced bronchoconstriction. In 10 pentobarbital-anesthetized ventilated sheep, the bronchial branch of the bronchoesophageal artery was cannulated and perfused (0.7 ml·min-1·kg-1) with blood pumped from the femoral artery. MCh was infused directly into the bronchial artery at increasing concentrations (10-7 to 10-5 M). MCh infusion caused a concentration-dependent increase in airway resistance at constant Q̇(BA). However, the time constant of recovery (TC) from airway constriction after cessation of the MCh infusion was not dependent on the MCh concentration or the magnitude of the increases in airway resistance. When Q̇(BA) was at 50, 100, and 200% of control level, with constant MCh concentration, TC was 44 ± 6, 25 ± 2, and 24 ± 2 (SE) s at each flow level, respectively. TC at 50% of control Q̇(BA) was significantly greater than at control Q̇(BA) (P <0.01). Thus the magnitude of Q̇(BA) can alter the time course of recovery from MCh-induced increases in airway resistance. These results document the importance of Q̇(BA) in reversing agonist-induced constriction and suggest that an impaired bronchial circulation may contribute to the mechanism of airway hyperreactivity.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 1220-1224 |
| Number of pages | 5 |
| Journal | Journal of Applied Physiology |
| Volume | 69 |
| Issue number | 4 |
| State | Published - 1990 |
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Keywords
- airway hyperreactivity
- airway resistance
- bronchial artery
- sheep
ASJC Scopus subject areas
- Endocrinology
- Physiology
- Orthopedics and Sports Medicine
- Physical Therapy, Sports Therapy and Rehabilitation
Cite this
Bronchial circulatory reversal of methacholine-induced airway constriction. / Wagner, Elizabeth Marie; Mitzner, Wayne A.
In: Journal of Applied Physiology, Vol. 69, No. 4, 1990, p. 1220-1224.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Bronchial circulatory reversal of methacholine-induced airway constriction
AU - Wagner, Elizabeth Marie
AU - Mitzner, Wayne A
PY - 1990
Y1 - 1990
N2 - Although a role for the bronchial circulation in clearance of bronchoactive agents has been frequently proposed, experimental evidence is limited. In this study, we determined the importance of bronchial blood flow (Q̇(BA)) in the recovery from methacholine-(MCh) induced bronchoconstriction. In 10 pentobarbital-anesthetized ventilated sheep, the bronchial branch of the bronchoesophageal artery was cannulated and perfused (0.7 ml·min-1·kg-1) with blood pumped from the femoral artery. MCh was infused directly into the bronchial artery at increasing concentrations (10-7 to 10-5 M). MCh infusion caused a concentration-dependent increase in airway resistance at constant Q̇(BA). However, the time constant of recovery (TC) from airway constriction after cessation of the MCh infusion was not dependent on the MCh concentration or the magnitude of the increases in airway resistance. When Q̇(BA) was at 50, 100, and 200% of control level, with constant MCh concentration, TC was 44 ± 6, 25 ± 2, and 24 ± 2 (SE) s at each flow level, respectively. TC at 50% of control Q̇(BA) was significantly greater than at control Q̇(BA) (P <0.01). Thus the magnitude of Q̇(BA) can alter the time course of recovery from MCh-induced increases in airway resistance. These results document the importance of Q̇(BA) in reversing agonist-induced constriction and suggest that an impaired bronchial circulation may contribute to the mechanism of airway hyperreactivity.
AB - Although a role for the bronchial circulation in clearance of bronchoactive agents has been frequently proposed, experimental evidence is limited. In this study, we determined the importance of bronchial blood flow (Q̇(BA)) in the recovery from methacholine-(MCh) induced bronchoconstriction. In 10 pentobarbital-anesthetized ventilated sheep, the bronchial branch of the bronchoesophageal artery was cannulated and perfused (0.7 ml·min-1·kg-1) with blood pumped from the femoral artery. MCh was infused directly into the bronchial artery at increasing concentrations (10-7 to 10-5 M). MCh infusion caused a concentration-dependent increase in airway resistance at constant Q̇(BA). However, the time constant of recovery (TC) from airway constriction after cessation of the MCh infusion was not dependent on the MCh concentration or the magnitude of the increases in airway resistance. When Q̇(BA) was at 50, 100, and 200% of control level, with constant MCh concentration, TC was 44 ± 6, 25 ± 2, and 24 ± 2 (SE) s at each flow level, respectively. TC at 50% of control Q̇(BA) was significantly greater than at control Q̇(BA) (P <0.01). Thus the magnitude of Q̇(BA) can alter the time course of recovery from MCh-induced increases in airway resistance. These results document the importance of Q̇(BA) in reversing agonist-induced constriction and suggest that an impaired bronchial circulation may contribute to the mechanism of airway hyperreactivity.
KW - airway hyperreactivity
KW - airway resistance
KW - bronchial artery
KW - sheep
UR - http://www.scopus.com/inward/record.url?scp=0025133152&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0025133152&partnerID=8YFLogxK
M3 - Article
C2 - 2262439
AN - SCOPUS:0025133152
VL - 69
SP - 1220
EP - 1224
JO - Journal of Applied Physiology
JF - Journal of Applied Physiology
SN - 0161-7567
IS - 4
ER -