Abstract
The purpose of this study was to test the hypothesis that blood flow, by its effect on blood volume, influences airflow resistance in peripheral airways. In conscious ewes, forced sinusoidal flow oscillations (5 Hz) were applied through a balloon-tipped, dual-channel fiberoptic bronchoscope placed in a segmental bronchus, and peripheral airflow resistance (R(p)) was determined from flow and bronchial pressure. Drugs with predominant vascular or airway smooth muscle effects were administered locally through the bronchoscope. Nitroglycerin (NTG) produced a dose-dependent increase in mean R(p) (+288% at 1,000 μg), which was blocked by methylene blue (p<0.05) and not reversed by atropine. Carbachol (CARB) also increased mean R(p) in a dose-dependent manner (+605% at 400 μg); this effect was not blocked by methylene blue, but it was reversed by atropine (p<0.05). The increase in mean R(p) after a single dose of NTG (250 μg) was sustained for at least 20 min and transiently reversed by vasopressin (0.2 units, p<0.05) but not by isoproterenol (100 μg). Conversely, the sustained increase in R(p) after a single dose of CARB (50 μg) was transiently reversed by isoproterenol (p<0.05) but not by vasopressin. We conclude that NTG increased R(p) by vasodilation and CARB by bronchoconstriction. This supports the hypothesis that vasodilation limits airflow in the lung periphery, presumably because of vascular congestion.
| Original language | English |
|---|---|
| Pages (from-to) | 1409-1413 |
| Number of pages | 5 |
| Journal | American Review of Respiratory Disease |
| Volume | 141 |
| Issue number | 6 |
| State | Published - Jan 1 1990 |
Fingerprint
ASJC Scopus subject areas
- Pulmonary and Respiratory Medicine
Cite this
Vasomotion influences airflow in peripheral airways. / Csete, M. E.; Abraham, W. M.; Wanner, Adam.
In: American Review of Respiratory Disease, Vol. 141, No. 6, 01.01.1990, p. 1409-1413.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Vasomotion influences airflow in peripheral airways
AU - Csete, M. E.
AU - Abraham, W. M.
AU - Wanner, Adam
PY - 1990/1/1
Y1 - 1990/1/1
N2 - The purpose of this study was to test the hypothesis that blood flow, by its effect on blood volume, influences airflow resistance in peripheral airways. In conscious ewes, forced sinusoidal flow oscillations (5 Hz) were applied through a balloon-tipped, dual-channel fiberoptic bronchoscope placed in a segmental bronchus, and peripheral airflow resistance (R(p)) was determined from flow and bronchial pressure. Drugs with predominant vascular or airway smooth muscle effects were administered locally through the bronchoscope. Nitroglycerin (NTG) produced a dose-dependent increase in mean R(p) (+288% at 1,000 μg), which was blocked by methylene blue (p<0.05) and not reversed by atropine. Carbachol (CARB) also increased mean R(p) in a dose-dependent manner (+605% at 400 μg); this effect was not blocked by methylene blue, but it was reversed by atropine (p<0.05). The increase in mean R(p) after a single dose of NTG (250 μg) was sustained for at least 20 min and transiently reversed by vasopressin (0.2 units, p<0.05) but not by isoproterenol (100 μg). Conversely, the sustained increase in R(p) after a single dose of CARB (50 μg) was transiently reversed by isoproterenol (p<0.05) but not by vasopressin. We conclude that NTG increased R(p) by vasodilation and CARB by bronchoconstriction. This supports the hypothesis that vasodilation limits airflow in the lung periphery, presumably because of vascular congestion.
AB - The purpose of this study was to test the hypothesis that blood flow, by its effect on blood volume, influences airflow resistance in peripheral airways. In conscious ewes, forced sinusoidal flow oscillations (5 Hz) were applied through a balloon-tipped, dual-channel fiberoptic bronchoscope placed in a segmental bronchus, and peripheral airflow resistance (R(p)) was determined from flow and bronchial pressure. Drugs with predominant vascular or airway smooth muscle effects were administered locally through the bronchoscope. Nitroglycerin (NTG) produced a dose-dependent increase in mean R(p) (+288% at 1,000 μg), which was blocked by methylene blue (p<0.05) and not reversed by atropine. Carbachol (CARB) also increased mean R(p) in a dose-dependent manner (+605% at 400 μg); this effect was not blocked by methylene blue, but it was reversed by atropine (p<0.05). The increase in mean R(p) after a single dose of NTG (250 μg) was sustained for at least 20 min and transiently reversed by vasopressin (0.2 units, p<0.05) but not by isoproterenol (100 μg). Conversely, the sustained increase in R(p) after a single dose of CARB (50 μg) was transiently reversed by isoproterenol (p<0.05) but not by vasopressin. We conclude that NTG increased R(p) by vasodilation and CARB by bronchoconstriction. This supports the hypothesis that vasodilation limits airflow in the lung periphery, presumably because of vascular congestion.
UR - http://www.scopus.com/inward/record.url?scp=0025297720&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0025297720&partnerID=8YFLogxK
M3 - Article
VL - 141
SP - 1409
EP - 1413
JO - American Journal of Respiratory and Critical Care Medicine
JF - American Journal of Respiratory and Critical Care Medicine
SN - 1073-449X
IS - 6
ER -