Autonomic regulation of cardiovascular function in neonates.
Autonomic regulation of cardiovascular function in neonates.
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新生儿心血管功能的自主调节。
DOI：
10.1002/9780470720653.ch4
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发表时间：
1981
期刊：
影响因子：
--
通讯作者：
Altura,BM
中科院分区：
文献类型：
--
作者：
Gootman,PM;Gootman,N;Turlapaty,PD;Yao,AC;Buckley,BJ;Altura,BM
在仔猪中，年龄从出生到两个月不等，评价了由上级肠系膜动脉供应的血管床在出生后成熟期间自主调节心血管功能的参与程度。动物麻醉与0.25-0.5%氟烷在50%的N2 O和O2的混合物，麻醉与十甲溴铵和人工通气，以保持正常的动脉血气和pH值。肠系膜动脉流量连续记录与电磁流量传感器，同时主动脉压，心率，股动脉，肾动脉和颈动脉流量进行监测。阻力计算为平均主动脉压与平均流量的比值。心血管系统的中枢神经调节被改变：（1）通过对延髓血管活性部位的电刺激，（2）通过改变来自内脏或躯体传入的输入，以及（3）通过使动物经受应激，如出血或缺氧。在体内和体外研究了肾上腺素能激动剂的辅助下肾上腺素能机制的出生后发育（将从上级肠系膜动脉切下的螺旋条置于器官浴中进行等长张力记录）。自发传出内脏放电的记录允许更直接的检查肠系膜血管床的自主调节。结果表明，由上级肠系膜动脉和内脏传出神经支配的血管床是积极参与心血管反应的心血管调节系统的改变。此外，该血管床可能对进食和应激都有不适当的反应，从而可能导致胃肠道的病理变化。
The degree of participation of the vascular bed supplied by the superior mesenteric artery in autonomic regulation of cardiovascular function during postnatal maturation was evaluated in piglets, ranging in age from birth to two months. Animals were anaesthetized with 0.25-0.5% halothane in a 50% mixture of N2O and O2, paralysed with decamethonium bromide and artificially ventilated to maintain normal arterial blood gases and pH. Mesenteric arterial flow was recorded continuously with an electromagnetic flow transducer; simultaneously aortic pressure, heart rate, and femoral, renal and carotid flows were monitored. Resistance was calculated as the ratio of mean aortic pressure to mean flow. The central neural regulation of the cardiovascular system was altered:(1) by electrical stimulation of medullary vasoactive sites,(2) by changing the input from visceral or somatic afferents and (3) by subjecting the animals to stress, such as haemorrhage or hypoxia. Postnatal development of adrenergic mechanisms was studied with the aid of adrenergic agonist both in vivo and in vitro (helical strips cut from superior mesenteric artery were placed in an organ bath for isometric tension recordings). Recordings of spontaneous efferent splanchnic discharge permitted a more direct examination of autonomic regulation of the mesenteric vascular bed. The results indicate that the vascular bed supplied by the superior mesenteric artery and innervated by the efferent splanchnic nerve is actively involved in the cardiovascular responses to alterations in the cardiovascular regulatory system. Furthermore, this vascular bed may have an inappropriate response to both feeding and stress such that pathological changes in the gastrointestinal tract may result.