Zhang Dongmei, Ando Motonori, Yamasaki Fumiyasu, Sato Takayuki
Department of Cardiovascular Control, Kochi Medical School, Nankoku, 783-8505 Japan.
Jpn J Physiol. 2003 Dec;53(6):461-6. doi: 10.2170/jjphysiol.53.461.
The neural mechanisms of the thermoregulatory control of core and skin temperatures in response to heat and cold stresses have been well clarified. However, it has been unclear whether baroreceptor reflexes are involved in the control of core and skin temperatures. To investigate how the arterial baroreceptor reflex modulates the body temperatures, we examined the effect of pressure changes of carotid sinus baroreceptors on core and skin temperatures in halothane-anesthetized rats. To open the baroreflex loop and control arterial baroreceptor pressure (BRP), we cut vagal and aortic depressor nerves and isolated carotid sinuses. We sequentially altered BRP in 20-mmHg increments from 60 to 180 mmHg and then in 20-mmHg decrements from 180 to 60 mmHg while measuring systemic arterial pressure (SAP), heart rate (HR), and core blood temperature (T(core)) at the aortic arch and skin temperature (T(skin)) at the tail. In response to the incremental change in BRP by 120 mmHg, SAP, HR, and T(core) fell by 90.3 +/- 5.1 mmHg, 60.3 +/- 10.5 beats min(-1), and 0.18 +/- 0.01 degrees C, respectively. T(skin) rose by 0.84 +/- 0.10 degrees C. The maximum rate of change per unit BRP change was -2.1 +/- 0.2 for SAP, -1.5 +/- 0.4 beats min(-1) mmHg(-1) for HR, -0.003 +/- 0.001 degrees C mmHg(-1) for T(core), and 0.011 +/- 0.002 degrees C mmHg(-1) for T(skin). After the administration of hexamethonium or bretylium, these baroreflexogenic responses were completely abolished. We concluded that T(core) and T(skin) are modulated by the arterial baroreceptor reflex.
核心体温和皮肤温度对热应激和冷应激的体温调节控制的神经机制已得到充分阐明。然而，尚不清楚压力感受器反射是否参与核心体温和皮肤温度的控制。为了研究动脉压力感受器反射如何调节体温，我们在氟烷麻醉的大鼠中检查了颈动脉窦压力感受器压力变化对核心体温和皮肤温度的影响。为了打开压力反射环路并控制动脉压力感受器压力（BRP），我们切断了迷走神经和主动脉减压神经，并分离出颈动脉窦。我们以20 mmHg的增量将BRP从60 mmHg依次改变至180 mmHg，然后以20 mmHg的减量从180 mmHg改变至60 mmHg，同时测量主动脉弓处的全身动脉压（SAP）、心率（HR）和核心体温（T(core)）以及尾部的皮肤温度（T(skin)）。响应于BRP增加120 mmHg，SAP、HR和T(core)分别下降90.3±5.1 mmHg、60.3±10.5次/分钟和0.18±0.01℃。T(skin)升高0.84±0.10℃。单位BRP变化的最大变化率对于SAP为-2.1±0.2，对于HR为-1.5±0.4次/分钟·mmHg⁻¹，对于T(core)为-0.003±0.001℃·mmHg⁻¹，对于T(skin)为0.011±0.002℃·mmHg⁻¹。给予六甲铵或溴苄铵后，这些压力反射性反应完全消失。我们得出结论，T(core)和T(skin)受动脉压力感受器反射调节。
