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Titolo:
CAROTID BAROREFLEX RESPONSIVENESS DURING DYNAMIC EXERCISE IN HUMANS
Autore:
POTTS JT; SHI XRR; RAVEN PB;
Indirizzi:
TEXAS COLL OSTEOPATH MED,DEPT PHYSIOL,3500 CAMP BOWIE BLVD FT WORTH TX 76107 TEXAS COLL OSTEOPATH MED,DEPT PHYSIOL,3500 CAMP BOWIE BLVD FT WORTH TX 76107
Titolo Testata:
The American journal of physiology
fascicolo: 6, volume: 265, anno: 1993,
parte:, 2
pagine: 80001928 - 80001938
SICI:
0002-9513(1993)265:6<80001928:CBRDDE>2.0.ZU;2-6
Fonte:
ISI
Lingua:
ENG
Soggetto:
SINUS BARORECEPTOR REFLEX; ARTERIAL-PRESSURE; BLOOD-PRESSURE; SYMPATHETIC ACTIVITY; AORTIC-ARCH; HEART-RATE; VOLUME;
Keywords:
CAROTID BARORECEPTORS; HEART RATE; BLOOD PRESSURE; OPERATING POINT PRESSURE; CENTERING POINT PRESSURE; THRESHOLD PRESSURE; SATURATION PRESSURE;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Science Citation Index Expanded
Citazioni:
33
Recensione:
Indirizzi per estratti:
Citazione:
J.T. Potts et al., "CAROTID BAROREFLEX RESPONSIVENESS DURING DYNAMIC EXERCISE IN HUMANS", The American journal of physiology, 265(6), 1993, pp. 80001928-80001938

Abstract

We utilized 5-s changes of neck pressure and neck suction (from 40 to-80 Torr) to alter carotid sinus carotid sinus perturbation were usedto construct open-loop baroreflex curves at rest and during exercise at 25.7 +/- 1.1 and 47.4 +/- 1.9% VO2peak. The baroreflex curves were fit to a logistic function describing the sigmoidal nature of the carotid sinus baroreceptor reflex. Maximal gain for baroreflex control of HR (-0.31 +/- 0.05 beats . min-1 . mmHg-1) and MAP (-0.30 +/- 0.08 mmHg/mmHg) at rest was the same as during exercise at 25 and 50% VO2peak (-0.30 +/- 0.05, -0.39 +/- 0.13 beats . min-1 . mmHg-1 for HR, P = NS;-0.23 +/- 0.04, -0.60 +/- 0.38 mmHg/mmHg for MAP, P = NS). Resetting of the baroreflex occurred during exercise at 50% VO2peak. The centering point, threshold, and saturation pressures were significantly increased for baroreflex control of HR (DELTApressure = 26.3 +/- 6.8, 19.6 /- 10.4, 33.0 +/- 5.6 mmHg, P < 0.05) and MAP (DELTApressure = 27.1 +/- 7.7, 16.1 +/- 14.8, 38.2 +/- 8.5 mmHg, P < 0.05). The operating point (steady-state HR and MAP) was shifted closer to threshold of the baroreflex during exercise at 50% VO2peak, as reflected by differences in HR and MAP between the centering and operating points (DELTAHR = 12.5 +/- 4.7 beats/min, P = 0.10; DELTAMAP = 7.6 +/- 1.3 mmHg, P < 0.05). These findings suggest a resetting of the carotid baroreflex during exercise with no attenuation in maximal sensitivity. A shift in operating point toward threshold of the baroreflex enables effective buffering of elevations in systemic blood pressure via reflex alterations in HR and MAP.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 11/07/20 alle ore 03:22:16