Effects of induced hypothermia on renal sympathetic nerve activity and baroreceptor reflex in urethane-anesthetized rabbits
| Autor: | Satoshi Yokono, Keisuke Seki, M. Aibiki, Shinji Ogura, Hui Xu, Kenji Ogli |
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| Rok vydání: | 2000 |
| Předmět: |
Mean arterial pressure
Sympathetic nervous system Baroreceptor Central Venous Pressure medicine.medical_treatment Vagotomy Baroreflex Kidney Critical Care and Intensive Care Medicine Urethane Body Temperature Random Allocation Catecholamines Heart Rate Hypothermia Induced medicine Animals Homeostasis Humans Sympathectomy business.industry Hemodynamics Carotid sinus Hypothermia Autonomic nervous system medicine.anatomical_structure Anesthesia Rabbits Blood Gas Analysis medicine.symptom Adrenergic Fibers business Anesthetics Intravenous |
| Zdroj: | Scopus-Elsevier |
| ISSN: | 0090-3493 |
| DOI: | 10.1097/00003246-200012000-00019 |
| Popis: | Objective To evaluate the role of the autonomic nervous system in hemodynamic changes during induced hypothermia. Design Prospective, randomized animal study. Setting An animal research laboratory in a medical university. Subjects A total of 29 anesthetized rabbits. Interventions Animals were anesthetized by intraperitoneal urethane. After tracheostomy and administration of gallamine, respiration was maintained by mechanical ventilatory support. The animals were divided into five groups (one control and the four experimental groups); animals were treated with an intact neuraxis and normothermia (control group), animals with an intact neuraxis (intact group), cervical vagotomized animals (vagotomy group), the carotid sinus and aortic nerves denervated animals (SAD group), and animals with SAD plus vagotomy (SADV group). The left renal sympathetic nerves were exposed by a retroperitoneal approach. Measurements and main results We examined the effects of surface cooling on HR, mean arterial pressure, central venous pressure, and renal sympathetic nerve activity (RSNA) in the animals. Changes of baroreflex sensitivity and plasma catecholamines were also measured simultaneously. Surface cooling caused progressive and profound decreases in HR in all experimental groups. In all groups, RSNAs increased at the early phase, which were followed by return to the precooling level. Conclusions Hemodynamics and RSNA during induced hypothermia are regulated by mechanisms other than the baroreceptor reflex system, possibly the dermal cold receptors. Suppression of the baroreflex occurred on HR but not on RSNA during hypothermia, which may indicate direct effects of hypothermia on the heart. RSNA responses may be activated earlier than systemic catecholamine responses during induced hypothermia. |
| Databáze: | OpenAIRE |
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