Abstract
We hypothesized that lumbar sympathetic nerve activity (LSNA) increases at the onset of whole-body dynamic exercise in the rat. To test this hypothesis, we recorded LSNA, heart rate (HR), and arterial pressure (AP) at rest and during a graded exercise test in six adult rats. Rats were instrumented with arterial and venous catheters and recording electrodes around the lumbar sympathetic trunk. Following recovery, each rat ran continuously on a hand- driven or motorized treadmill at 6 m·min-1, 12 m·min-1, and 18 m-min- 1 on a 10% grade for approximately 3 min at each workload. Before exercise, mean arterial pressure (MAP), HR, and LSNA averaged 108 ± 4 mm Hg, 385 ± 20 bpm, and 100%, respectively. As hypothesized, all variables increased abruptly and dramatically at the onset of treadmill exercise. For example, MAP (117 ± 5 mm Hg), HR (450 ± 15 bpm), and LSNA (225 ± 19%) all increased significantly within the first 25 s of treadmill running at 6 m·min-1. As the exercise continued, there was a progressive increase in HR; however, MAP plateaued at 6 m·min-1 and LSNA plateaued at 12 m·min-1. Since LSNA increased at the onset of whole-body dynamic exercise in the rat, we suggest that the increase in LSNA at the onset of exercise is mediated by a central (feed forward) mechanism.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 677-684 |
| Number of pages | 8 |
| Journal | Medicine and Science in Sports and Exercise |
| Volume | 28 |
| Issue number | 6 |
| DOIs | |
| State | Published - Jun 1996 |
| Externally published | Yes |
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Keywords
- BAROREFLEX RESETTING
- BLOOD PRESSURE
- HEART RATE
- TREADMILL EXERCISE
ASJC Scopus subject areas
- Public Health, Environmental and Occupational Health
- Physical Therapy, Sports Therapy and Rehabilitation
- Orthopedics and Sports Medicine
Cite this
Onset of exercise increases lumbar sympathetic nerve activity in rats. / DiCarlo, Stephen E.; Chen, Chao-Yin; Collins, Heidi L.
In: Medicine and Science in Sports and Exercise, Vol. 28, No. 6, 06.1996, p. 677-684.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Onset of exercise increases lumbar sympathetic nerve activity in rats
AU - DiCarlo, Stephen E.
AU - Chen, Chao-Yin
AU - Collins, Heidi L.
PY - 1996/6
Y1 - 1996/6
N2 - We hypothesized that lumbar sympathetic nerve activity (LSNA) increases at the onset of whole-body dynamic exercise in the rat. To test this hypothesis, we recorded LSNA, heart rate (HR), and arterial pressure (AP) at rest and during a graded exercise test in six adult rats. Rats were instrumented with arterial and venous catheters and recording electrodes around the lumbar sympathetic trunk. Following recovery, each rat ran continuously on a hand- driven or motorized treadmill at 6 m·min-1, 12 m·min-1, and 18 m-min- 1 on a 10% grade for approximately 3 min at each workload. Before exercise, mean arterial pressure (MAP), HR, and LSNA averaged 108 ± 4 mm Hg, 385 ± 20 bpm, and 100%, respectively. As hypothesized, all variables increased abruptly and dramatically at the onset of treadmill exercise. For example, MAP (117 ± 5 mm Hg), HR (450 ± 15 bpm), and LSNA (225 ± 19%) all increased significantly within the first 25 s of treadmill running at 6 m·min-1. As the exercise continued, there was a progressive increase in HR; however, MAP plateaued at 6 m·min-1 and LSNA plateaued at 12 m·min-1. Since LSNA increased at the onset of whole-body dynamic exercise in the rat, we suggest that the increase in LSNA at the onset of exercise is mediated by a central (feed forward) mechanism.
AB - We hypothesized that lumbar sympathetic nerve activity (LSNA) increases at the onset of whole-body dynamic exercise in the rat. To test this hypothesis, we recorded LSNA, heart rate (HR), and arterial pressure (AP) at rest and during a graded exercise test in six adult rats. Rats were instrumented with arterial and venous catheters and recording electrodes around the lumbar sympathetic trunk. Following recovery, each rat ran continuously on a hand- driven or motorized treadmill at 6 m·min-1, 12 m·min-1, and 18 m-min- 1 on a 10% grade for approximately 3 min at each workload. Before exercise, mean arterial pressure (MAP), HR, and LSNA averaged 108 ± 4 mm Hg, 385 ± 20 bpm, and 100%, respectively. As hypothesized, all variables increased abruptly and dramatically at the onset of treadmill exercise. For example, MAP (117 ± 5 mm Hg), HR (450 ± 15 bpm), and LSNA (225 ± 19%) all increased significantly within the first 25 s of treadmill running at 6 m·min-1. As the exercise continued, there was a progressive increase in HR; however, MAP plateaued at 6 m·min-1 and LSNA plateaued at 12 m·min-1. Since LSNA increased at the onset of whole-body dynamic exercise in the rat, we suggest that the increase in LSNA at the onset of exercise is mediated by a central (feed forward) mechanism.
KW - BAROREFLEX RESETTING
KW - BLOOD PRESSURE
KW - HEART RATE
KW - TREADMILL EXERCISE
UR - http://www.scopus.com/inward/record.url?scp=0029882869&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0029882869&partnerID=8YFLogxK
U2 - 10.1097/00005768-199606000-00006
DO - 10.1097/00005768-199606000-00006
M3 - Article
C2 - 8784755
AN - SCOPUS:0029882869
VL - 28
SP - 677
EP - 684
JO - Medicine and Science in Sports and Exercise
JF - Medicine and Science in Sports and Exercise
SN - 0195-9131
IS - 6
ER -