Effects of central venous blood volume shifts on arterial baroreflex control of heart rate
| Autor: | K. K. Teoh, H. L. Stone, D. T. Dickey, George E. Billman |
|---|---|
| Rok vydání: | 1981 |
| Předmět: |
Male
Physiology medicine.medical_treatment Posture Plasma Substitutes Pressoreceptors Blood volume Baroreflex Heart Rate Physiology (medical) Reflex Heart rate Animals Medicine Anesthesia Saline Phenylephrine Blood Volume business.industry Venous blood Macaca mulatta Propranolol Head-Down Tilt Aortic pressure Macaca Cardiology and Cardiovascular Medicine business medicine.drug |
| Zdroj: | American Journal of Physiology-Heart and Circulatory Physiology. 241:H571-H575 |
| ISSN: | 1522-1539 0363-6135 |
| DOI: | 10.1152/ajpheart.1981.241.4.h571 |
| Popis: | The purpose of this study was to investigate the effects of anesthesia, body position, and blood volume expansion on baroreflex control of heart rate. Five male rhesus monkeys (7.0-10.5 kg) were given bolus injection of 4.0 micrograms/kg phenylephrine during each of the following situations: awake sitting, anesthetized (AN) (10 mg/kg ketamine-HCl) sitting, AN recumbent, AN 90 degrees head down tilt, and AN 50% blood volume expansion with normal saline. beta-Receptor blockade was also performed on each treatment after anesthesia. Four additional animals were similarly treated after 20% blood volume expansion. R-R interval was plotted against systolic aortic pressure, and the slope was determined by linear regression. Baroreflex slope was significantly (P less than 0.05) reduced by 90 degrees head down tilt and 50% volume expansion both before and after beta-receptor blockade. A similar trend was seen after 20% volume expansion. These data are consistent with the thesis that baroreflex control of heart rate is reduced by central blood volume shifts. |
| Databáze: | OpenAIRE |
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