Abstract
In anesthetized rabbits with sinus and aortic nerves cut, when the cervical vagal nerves were cooled to 12, 8, 6, and 0°C, there were progressive increases in aortic blood pressure of 7 ± 1, 15 ± 2, 25 ± 1, and 41 ± 2 mmHg (SE), respectively. For comparison, during cooling of the aortic and vagal nerves, at 12°C there was a decrease in firing in the afferent fibers from aortic baroreceptors (48 ± 4%) and pulmonary stretch receptors (57 ± 5%), and at 6°C all activity was abolished. Thus, at 6°C the activity in medullated fibers from the aortic baroreceptors and pulmonary stretch receptors is blocked, but the increase in aortic blood pressure with vagal cooling is only 60% of that with cooling to 0°C. This demonstrates that cardiopulmonary receptors with nonmedullated vagal afferents (C fibers) contribute to the tonic inhibition of the vasomotor center. Because of overlap in sensitivity of different vagal fibers to cooling, the total contribution of these C fibers cannot be evaluated.
| Original language | English |
|---|---|
| Title of host publication | American Journal of Physiology |
| Pages | 1410-1413 |
| Number of pages | 4 |
| Volume | 229 |
| Edition | 5 |
| Publication status | Published - 1975 |
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ASJC Scopus subject areas
- Medicine(all)
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Vasomotor inhibition in rabbits by vagal nonmedullated fibers from cardiopulmonary area. / Thoren, P. N.; Mancia, G.; Shepherd, J. T.
American Journal of Physiology. Vol. 229 5. ed. 1975. p. 1410-1413.Research output: Chapter in Book/Report/Conference proceeding › Chapter
}
TY - CHAP
T1 - Vasomotor inhibition in rabbits by vagal nonmedullated fibers from cardiopulmonary area
AU - Thoren, P. N.
AU - Mancia, G.
AU - Shepherd, J. T.
PY - 1975
Y1 - 1975
N2 - In anesthetized rabbits with sinus and aortic nerves cut, when the cervical vagal nerves were cooled to 12, 8, 6, and 0°C, there were progressive increases in aortic blood pressure of 7 ± 1, 15 ± 2, 25 ± 1, and 41 ± 2 mmHg (SE), respectively. For comparison, during cooling of the aortic and vagal nerves, at 12°C there was a decrease in firing in the afferent fibers from aortic baroreceptors (48 ± 4%) and pulmonary stretch receptors (57 ± 5%), and at 6°C all activity was abolished. Thus, at 6°C the activity in medullated fibers from the aortic baroreceptors and pulmonary stretch receptors is blocked, but the increase in aortic blood pressure with vagal cooling is only 60% of that with cooling to 0°C. This demonstrates that cardiopulmonary receptors with nonmedullated vagal afferents (C fibers) contribute to the tonic inhibition of the vasomotor center. Because of overlap in sensitivity of different vagal fibers to cooling, the total contribution of these C fibers cannot be evaluated.
AB - In anesthetized rabbits with sinus and aortic nerves cut, when the cervical vagal nerves were cooled to 12, 8, 6, and 0°C, there were progressive increases in aortic blood pressure of 7 ± 1, 15 ± 2, 25 ± 1, and 41 ± 2 mmHg (SE), respectively. For comparison, during cooling of the aortic and vagal nerves, at 12°C there was a decrease in firing in the afferent fibers from aortic baroreceptors (48 ± 4%) and pulmonary stretch receptors (57 ± 5%), and at 6°C all activity was abolished. Thus, at 6°C the activity in medullated fibers from the aortic baroreceptors and pulmonary stretch receptors is blocked, but the increase in aortic blood pressure with vagal cooling is only 60% of that with cooling to 0°C. This demonstrates that cardiopulmonary receptors with nonmedullated vagal afferents (C fibers) contribute to the tonic inhibition of the vasomotor center. Because of overlap in sensitivity of different vagal fibers to cooling, the total contribution of these C fibers cannot be evaluated.
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M3 - Chapter
C2 - 1200162
AN - SCOPUS:0016645919
VL - 229
SP - 1410
EP - 1413
BT - American Journal of Physiology
ER -