Chapter title |
Arteriolar vasomotor control and contractile performance during fatiguing tetanic contractions in rat skeletal muscle: role of sympathetic system.
|
---|---|
Chapter number | 44 |
Book title |
Oxygen Transport to Tissue XXXI
|
Published in |
Advances in experimental medicine and biology, October 2009
|
DOI | 10.1007/978-1-4419-1241-1_44 |
Pubmed ID | |
Book ISBNs |
978-1-4419-1239-8, 978-1-4419-1241-1
|
Authors |
Inagaki T, Sonobe T, Poole DC, Kano Y, Tadakatsu Inagaki, Takashi Sonobe, David C. Poole, Yutaka Kano, Inagaki, Tadakatsu, Sonobe, Takashi, Poole, David C., Kano, Yutaka |
Editors |
Eiji Takahashi, Duane F. Bruley |
Abstract |
Using a fatiguing stimulation protocol designed specifically to enhance sympathetically-mediated vasoconstrictor tone, we explored the temporal profile of the evoked vasoconstrictor response, evaluated the presence of sympatholysis, and assessed the role of alpha1-adrenergic receptor-mediated vasoconstriction on muscle performance. Spinotrapezius muscles of Wistar rats were exteriorized and stimulated tetanically (100 Hz, 4-7 V, stimulus duration 700 ms) every 3 s for 2.5 min under control and prazosin (1 muM) superfused conditions. The extent and time course of diameter changes in arterioles (2 A) and venules (2 V) were determined after each of 10 discrete sets of muscle stimulation at 5-min intervals. A significant decrease of luminal diameter was observed in arterioles after tetanic contractions at 8-10 sets (8 sets: -34.4%, 9 sets: -39.4%, 10 sets: -38.6% vs pre-contraction at each set, p < 0.01). Prazosin significantly reduced but did not abolish the contraction-induced vasoconstriction. In both conditions, there was no reduction of venules diameter observed. Tetanic contractions force at the final 10th set was significantly decreased to 29.3 +/- 11.9% from pre-fatigue conditions, while tetanic contractions with prazosin force production was maintained at 70.4 +/- 14.2% at the 10th set. We conclude that in sequential bouts of contractions there was a progressively greater degree of arteriolar (but not venular) vasoconstriction which was attenuated substantially by prazosin. |
X Demographics
Geographical breakdown
Country | Count | As % |
---|---|---|
United States | 1 | 100% |
Demographic breakdown
Type | Count | As % |
---|---|---|
Members of the public | 1 | 100% |
Mendeley readers
Geographical breakdown
Country | Count | As % |
---|---|---|
Unknown | 8 | 100% |
Demographic breakdown
Readers by professional status | Count | As % |
---|---|---|
Student > Ph. D. Student | 2 | 25% |
Researcher | 2 | 25% |
Other | 1 | 13% |
Unknown | 3 | 38% |
Readers by discipline | Count | As % |
---|---|---|
Medicine and Dentistry | 3 | 38% |
Agricultural and Biological Sciences | 1 | 13% |
Biochemistry, Genetics and Molecular Biology | 1 | 13% |
Unknown | 3 | 38% |