Abstract
Magnesium sulfate has been shown to be effective clinically as a bronchodilator, but its mechanism of action is unknown. We used a wedged bronchoscope technique to study the ability of MgSO4 at clinically relevant concentrations to attenuate hypocapnia-, acetylcholine- (ACh), and dry air-induced bronchoconstriction in the canine lung periphery. Control experiments demonstrated that consecutive challenges of either hypocapnia or ACh resulted in greater collateral system resistance (Rcs) after the second challenge compared with the first. Intravenous infusion of MgSO4 diminished the maximum response to a second hypocapnic challenge (Rcs = 1.59 ± 0.29 cmH2O·ml-1·s prechallenge vs. 1.12 ± 0.20 postchallenge) but had no effect on either ACh- or dry air-induced bronchoconstriction. Serum magnesium levels before MgSO4 administration were 1.59 ± 0.04 meq/l and rose to 6.20 ± 0.13 during the infusion. Previous studies demonstrated that nifedipine, like MgSO4 in this study, attenuates hypocapnia-induced bronchoconstriction in the canine lung periphery but has no effect on ACh- or dry air-induced bronchoconstriction. We conclude that these results are consistent with the idea that, like nifedipine, magnesium acts in the airway as a voltage-sensitive calcium channel blocker.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 2527-2532 |
| Number of pages | 6 |
| Journal | Journal of Applied Physiology |
| Volume | 66 |
| Issue number | 6 |
| State | Published - 1989 |
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ASJC Scopus subject areas
- Endocrinology
- Physiology
- Orthopedics and Sports Medicine
- Physical Therapy, Sports Therapy and Rehabilitation
Cite this
Effect of magnesium sulfate on bronchoconstriction in the lung periphery. / Lindeman, Karen Sue; Hirshman, C. A.; Freed, A. N.
In: Journal of Applied Physiology, Vol. 66, No. 6, 1989, p. 2527-2532.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Effect of magnesium sulfate on bronchoconstriction in the lung periphery
AU - Lindeman, Karen Sue
AU - Hirshman, C. A.
AU - Freed, A. N.
PY - 1989
Y1 - 1989
N2 - Magnesium sulfate has been shown to be effective clinically as a bronchodilator, but its mechanism of action is unknown. We used a wedged bronchoscope technique to study the ability of MgSO4 at clinically relevant concentrations to attenuate hypocapnia-, acetylcholine- (ACh), and dry air-induced bronchoconstriction in the canine lung periphery. Control experiments demonstrated that consecutive challenges of either hypocapnia or ACh resulted in greater collateral system resistance (Rcs) after the second challenge compared with the first. Intravenous infusion of MgSO4 diminished the maximum response to a second hypocapnic challenge (Rcs = 1.59 ± 0.29 cmH2O·ml-1·s prechallenge vs. 1.12 ± 0.20 postchallenge) but had no effect on either ACh- or dry air-induced bronchoconstriction. Serum magnesium levels before MgSO4 administration were 1.59 ± 0.04 meq/l and rose to 6.20 ± 0.13 during the infusion. Previous studies demonstrated that nifedipine, like MgSO4 in this study, attenuates hypocapnia-induced bronchoconstriction in the canine lung periphery but has no effect on ACh- or dry air-induced bronchoconstriction. We conclude that these results are consistent with the idea that, like nifedipine, magnesium acts in the airway as a voltage-sensitive calcium channel blocker.
AB - Magnesium sulfate has been shown to be effective clinically as a bronchodilator, but its mechanism of action is unknown. We used a wedged bronchoscope technique to study the ability of MgSO4 at clinically relevant concentrations to attenuate hypocapnia-, acetylcholine- (ACh), and dry air-induced bronchoconstriction in the canine lung periphery. Control experiments demonstrated that consecutive challenges of either hypocapnia or ACh resulted in greater collateral system resistance (Rcs) after the second challenge compared with the first. Intravenous infusion of MgSO4 diminished the maximum response to a second hypocapnic challenge (Rcs = 1.59 ± 0.29 cmH2O·ml-1·s prechallenge vs. 1.12 ± 0.20 postchallenge) but had no effect on either ACh- or dry air-induced bronchoconstriction. Serum magnesium levels before MgSO4 administration were 1.59 ± 0.04 meq/l and rose to 6.20 ± 0.13 during the infusion. Previous studies demonstrated that nifedipine, like MgSO4 in this study, attenuates hypocapnia-induced bronchoconstriction in the canine lung periphery but has no effect on ACh- or dry air-induced bronchoconstriction. We conclude that these results are consistent with the idea that, like nifedipine, magnesium acts in the airway as a voltage-sensitive calcium channel blocker.
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UR - http://www.scopus.com/inward/citedby.url?scp=0024370926&partnerID=8YFLogxK
M3 - Article
C2 - 2501286
AN - SCOPUS:0024370926
VL - 66
SP - 2527
EP - 2532
JO - Journal of Applied Physiology
JF - Journal of Applied Physiology
SN - 0161-7567
IS - 6
ER -