Abstract
1. Brief stimuli were delivered to the carotid baroreceptors or chemoreceptors in dogs anaesthetized with chloralose and paralysed with D-turbocurarine. Baroreceptor stimulation was achieved by forceful retrograde injection of 2-5 ml or air-equilibrated saline into the external carotid artery after first clamping the common carotid artery. Chemoreceptor stimulation was achieved by rapid retrograde injections of 0.2-0.5 ml of warmed CO2-equilibrated saline into the external carotid artery. Observations were made during periods of temporary cessation of artificial ventilation. 2. When the volume of the lungs was not changing, prompt decreases in heart rate were evoked by chemoreceptor or baroreceptor stimuli except when these were delivered during the inspiratory phase of breathing (as judged from the records of phrenic nerve activity). 3. No changes in heart rate were evoked when these stimuli were timed to occur during expansion of the lungs in response to a rapid increase in intratracheal pressure (6-10 mmHg in 1-2 sec). Decreases in heart rate were evoked when the stimuli occurred during slower inflations of the lungs. 4. Both stimuli regained their effectiveness on heart rate with time after inflations of the lung when the lungs were held inflated. Both stimuli evoked large decreases in heart rate when delivered during deflations of the lung. 5. The effects of lung inflation on the effectiveness of both cardiodepressor reflexes were abolished by surgical denervation of the lungs.
Full text
PDF
Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- DE DALY M. B., SCOTT M. J. The effects of stimulation of the carotid body chemoreceptors on heart rate in the dog. J Physiol. 1958 Nov 10;144(1):148–166. doi: 10.1113/jphysiol.1958.sp006092. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Davidson N. S., Goldner S., McCloskey D. I. Respiratory modulation of barareceptor and chemoreceptor reflexes affecting heart rate and cardiac vagal efferent nerve activity. J Physiol. 1976 Jul;259(2):523–530. doi: 10.1113/jphysiol.1976.sp011480. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Gandevia S. C., McCloskey D. I., Potter E. K. Inhibitory effects of lung inflation on cardiodepressor reflexes from baroreceptors and chemoreceptors [proceedings]. J Physiol. 1977 Oct;272(1):83P–84P. [PubMed] [Google Scholar]
- Gandevia S. C., McCloskey D. I., Potter E. K. Reflex bradycardia occurring in response to diving, nasopharyngeal stimulation and ocular pressure, and its modification by respiration and swallowing. J Physiol. 1978 Mar;276:383–394. doi: 10.1113/jphysiol.1978.sp012241. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Haymet B. T., McCloskey D. I. Baroreceptor and chemoreceptor influences on heart rate during the respiratory cycle in the dog. J Physiol. 1975 Mar;245(3):699–712. doi: 10.1113/jphysiol.1975.sp010869. [DOI] [PMC free article] [PubMed] [Google Scholar]
- KOEPCHEN H. P., WAGNER P. H., LUX H. D. [On the relationships between central excitation, reflex tone and respiratory rhythm in nervous regulation of heart frequency]. Pflugers Arch Gesamte Physiol Menschen Tiere. 1961;273:443–465. [PubMed] [Google Scholar]
- Levy M. N., DeGeest H., Zieske H. Effects of respiratory center activity on the heart. Circ Res. 1966 Jan;18(1):67–78. doi: 10.1161/01.res.18.1.67. [DOI] [PubMed] [Google Scholar]
- Lopes O. U., Palmer J. F. Proposed respiratory 'gating' mechanism for cardiac slowing. Nature. 1976 Dec 2;264(5585):454–456. doi: 10.1038/264454a0. [DOI] [PubMed] [Google Scholar]
- Paintal A. S. Vagal sensory receptors and their reflex effects. Physiol Rev. 1973 Jan;53(1):159–227. doi: 10.1152/physrev.1973.53.1.159. [DOI] [PubMed] [Google Scholar]
- Sampson S. R., Vidruk E. H. Properties of 'irritant' receptors in canine lung. Respir Physiol. 1975 Oct;25(1):9–22. doi: 10.1016/0034-5687(75)90047-x. [DOI] [PubMed] [Google Scholar]
- Streatfeild K. A., Davidson N. S., McCloskey D. I. Muscular reflex and baroreflex influences on heart rate during isometric contractions. Cardiovasc Res. 1977 Mar;11(2):87–93. doi: 10.1093/cvr/11.2.87. [DOI] [PubMed] [Google Scholar]