Signal transduction of aortic and carotid sinus baroreceptors is not modified by central command during spontaneous motor activity in decerebrate cats
| Autor: | Tomoko Ishida, Akito Kadowaki, Kanji Matsukawa, Nan Liang, Kei Ishii, Mitsuhiro Idesako |
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| Rok vydání: | 2014 |
| Předmět: |
Central Nervous System
medicine.medical_specialty Baroreceptor Physiology Blood Pressure Pressoreceptors Motor Activity Baroreflex Selective inhibition Heart Rate Cerebellum Physiology (medical) Internal medicine Animals Medicine Motor activity Cardiac Output Decerebrate State business.industry Carotid sinus Sinus of Valsalva Decerebrate cats Carotid Sinus medicine.anatomical_structure Anesthesia Models Animal Cats cardiovascular system Cardiology Signal transduction business Signal Transduction circulatory and respiratory physiology |
| Zdroj: | American Journal of Physiology-Regulatory, Integrative and Comparative Physiology. 306:R735-R746 |
| ISSN: | 1522-1490 0363-6119 |
| Popis: | Our laboratory has suggested that central command provides selective inhibition of the cardiomotor component of aortic baroreflex at the start of exercise, preserving carotid sinus baroreflex. It is postulated that central command may modify the signal transduction of aortic baroreceptors, so as to decrease aortic baroreceptor input to the cardiovascular centers, and, thereby, can cause the selective inhibition of aortic baroreflex. To test the hypothesis, we directly analyzed the responses in multifiber aortic nerve activity (AoNA) and carotid sinus nerve activity (CsNA) during spontaneous motor activity in decerebrate, paralyzed cats. The increases of 62–104% in mean AoNA and CsNA were found during spontaneous motor activity, in proportion to a rise of 35 ± 3 mmHg (means ± SE) in mean arterial blood pressure (MAP), and had an attenuating tendency by restraining heart rate (HR) at the lower intrinsic frequency of 154 ± 6 beats/min. Brief occlusion of the abdominal aorta was conducted before and during spontaneous motor activity to produce a mechanically evoked increase in MAP and, thereby, to examine the stimulus-response relationship of arterial baroreceptors. Although the sensitivity of the MAP-HR baroreflex curve was markedly blunted during spontaneous motor activity, the stimulus-response relationships of AoNA and CsNA were not influenced by spontaneous motor activity, irrespective of the absence or presence of the HR restraint. Thus, it is concluded that aortic and carotid sinus baroreceptors can code beat-by-beat blood pressure during spontaneous motor activity in decerebrate cats and that central command is unlikely to modulate the signal transduction of arterial baroreceptors. |
| Databáze: | OpenAIRE |
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