Abstract
Previous work from this laboratory has demonstrated that the chemical activation of cell bodies in the caudal ventrolateral medulla of chloralose-anesthetized dogs decreased bronchomotor tone by withdrawing cholinergic input to airway smooth muscle. In the present study we determined the bronchomotor responses to microinjection of DL-homocysteic acid (100 mM; 25-50 nl) into the rostral ventrolateral (RVL) medulla of chloralose-anesthetized dogs. Total lung resistance was used as a functional index of bronchomotor tone. Microinjection of DL-homocysteic acid into the 20 sites located in the lateral aspect of the RVL medulla increased both total lung resistance [from 6.5 ± 0.4 to 9.1 ± 0.8 (SE) cmH2O · 1-1 · s; P < 0.05] and mean arterial pressure (from 125 ± 5 to 148 ± 8 mmHg; P < 0.05). Microinjection of this amino acid into nine sites located in the medial aspect of the RVL medulla increased mean arterial pressure (from 130 ± 6 to 153 ± 6 mmHg; P < 0.05) but had no effect on total lung resistance. We confirmed in three sites that the increase in total lung resistance evoked by microinjection of DL-homocysteic acid was accompanied by an increase in tracheal smooth muscle tension. The increase in total lung resistance evoked by DL-homocysteic acid was not affected by β-adrenergic blockade but was abolished by muscarinic blockade.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 210-216 |
| Number of pages | 7 |
| Journal | Journal of Applied Physiology |
| Volume | 71 |
| Issue number | 1 |
| State | Published - 1991 |
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Keywords
- brain stem
- bronchoconstriction
- cholinergic blockade
- DL-homocysteic acid
- neural control of airways
ASJC Scopus subject areas
- Endocrinology
- Physiology
- Orthopedics and Sports Medicine
- Physical Therapy, Sports Therapy and Rehabilitation
Cite this
Activation of neurons in the rostral ventrolateral medulla increases bronchomotor tone in dogs. / Haselton, J. R.; Padrid, P. A.; Kaufman, Marc P.
In: Journal of Applied Physiology, Vol. 71, No. 1, 1991, p. 210-216.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Activation of neurons in the rostral ventrolateral medulla increases bronchomotor tone in dogs
AU - Haselton, J. R.
AU - Padrid, P. A.
AU - Kaufman, Marc P
PY - 1991
Y1 - 1991
N2 - Previous work from this laboratory has demonstrated that the chemical activation of cell bodies in the caudal ventrolateral medulla of chloralose-anesthetized dogs decreased bronchomotor tone by withdrawing cholinergic input to airway smooth muscle. In the present study we determined the bronchomotor responses to microinjection of DL-homocysteic acid (100 mM; 25-50 nl) into the rostral ventrolateral (RVL) medulla of chloralose-anesthetized dogs. Total lung resistance was used as a functional index of bronchomotor tone. Microinjection of DL-homocysteic acid into the 20 sites located in the lateral aspect of the RVL medulla increased both total lung resistance [from 6.5 ± 0.4 to 9.1 ± 0.8 (SE) cmH2O · 1-1 · s; P < 0.05] and mean arterial pressure (from 125 ± 5 to 148 ± 8 mmHg; P < 0.05). Microinjection of this amino acid into nine sites located in the medial aspect of the RVL medulla increased mean arterial pressure (from 130 ± 6 to 153 ± 6 mmHg; P < 0.05) but had no effect on total lung resistance. We confirmed in three sites that the increase in total lung resistance evoked by microinjection of DL-homocysteic acid was accompanied by an increase in tracheal smooth muscle tension. The increase in total lung resistance evoked by DL-homocysteic acid was not affected by β-adrenergic blockade but was abolished by muscarinic blockade.
AB - Previous work from this laboratory has demonstrated that the chemical activation of cell bodies in the caudal ventrolateral medulla of chloralose-anesthetized dogs decreased bronchomotor tone by withdrawing cholinergic input to airway smooth muscle. In the present study we determined the bronchomotor responses to microinjection of DL-homocysteic acid (100 mM; 25-50 nl) into the rostral ventrolateral (RVL) medulla of chloralose-anesthetized dogs. Total lung resistance was used as a functional index of bronchomotor tone. Microinjection of DL-homocysteic acid into the 20 sites located in the lateral aspect of the RVL medulla increased both total lung resistance [from 6.5 ± 0.4 to 9.1 ± 0.8 (SE) cmH2O · 1-1 · s; P < 0.05] and mean arterial pressure (from 125 ± 5 to 148 ± 8 mmHg; P < 0.05). Microinjection of this amino acid into nine sites located in the medial aspect of the RVL medulla increased mean arterial pressure (from 130 ± 6 to 153 ± 6 mmHg; P < 0.05) but had no effect on total lung resistance. We confirmed in three sites that the increase in total lung resistance evoked by microinjection of DL-homocysteic acid was accompanied by an increase in tracheal smooth muscle tension. The increase in total lung resistance evoked by DL-homocysteic acid was not affected by β-adrenergic blockade but was abolished by muscarinic blockade.
KW - brain stem
KW - bronchoconstriction
KW - cholinergic blockade
KW - DL-homocysteic acid
KW - neural control of airways
UR - http://www.scopus.com/inward/record.url?scp=0025764528&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0025764528&partnerID=8YFLogxK
M3 - Article
VL - 71
SP - 210
EP - 216
JO - Journal of Applied Physiology
JF - Journal of Applied Physiology
SN - 8750-7587
IS - 1
ER -