ADRENOMEDULLARY PRESSOR-RESPONSES DURING POSTERIOR HYPOTHALAMIC-STIMULATION
ADRENOMEDULLARY PRESSOR-RESPONSES DURING POSTERIOR HYPOTHALAMIC-STIMULATION
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DOI：
10.1152/ajplegacy.1974.227.1.114
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发表时间：
1974-01-01
影响因子：
--
通讯作者：
BUNAG, RD
中科院分区：
文献类型：
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作者：
EFERAKEYA, A;BUNAG, RD
方法雄性Wistar大鼠，体重240-280 g，用乌拉坦（1.25 g/kg ip）麻醉，颈静脉和腹主动脉插管。将两个导管的外端在皮肤下通过以在颈后露出，使得大鼠可以翻转并附接到立体定位装置（大卫科普夫仪器，图贡加，加利福尼亚州）。以俯卧的姿势。同轴电极，直径0.5 mm（罗兹医疗器械，Woodland Hills，CA）使用de Groot坐标：前后5.0，外侧1。O和背腹侧-2.5（11）。当用0.25 mA电流（频率90/s，脉宽1 ms）刺激10 s使收缩压增加20 mmHg以上时，电极定位正确。在一些实验之后，移除大鼠的大脑以在组织学上验证电极尖端在后下丘脑中，在乳头丘脑束内侧和第三脑室外侧;在它的前面是背内侧下丘脑核，在乳头体前核和乳头体上核的后面;在它的背侧是丘脑连合核，在腹侧是背侧乳头体前核（11）。在实验过程中，通过经由温度控制器（Yellow Springs Instruments Co.，Yellow Springs，俄亥俄州），主动脉导管中填充稀释的肝素溶液（ZOO U/ml），以尽量减少血液凝固。通过将主动脉导管连接到具有低容量位移的压力传感器（斯坦森P23 Gb）来连续监测相性动脉压。用生物速度计（Gould Inc.，Cleveland，俄亥俄州）由来自传感器的相位压力信号触发。对于电刺激，将下丘脑电极通过恒流单元（Grass Medical Instruments，昆西，MA）连接到固态方脉冲刺激器。除非另有说明，通常使用0.25mA的电流强度。通过颈静脉导管（4）注射所有药物，剂量表示为每只大鼠注射的相应盐的重量。所用药物为碘化1，1-二甲基-4-苯基哌嗪（DMPP）、硫酸乙啶（Ismelin）、重酒石酸去甲肾上腺素（Levophed）、酒石酸喷托啉（Ansolysen）、甲磺酸酚妥拉明（Regitine）、盐酸普萘洛尔（Inderal）和加压素（Pitressin）。拮抗剂分次注射。剂量，直到在0.25时对下丘脑刺激的升压反应没有进一步抑制
METHODSFemale Wistar rats weighing 240-280 g were anesthetized with urethan (1.25 g/kg ip), and catheters were inserted into a jugular vein and the lower abdominal aorta. The outer ends of both catheters were passed under the skin to emerge at the nape of the neck so that the rat could be turned over and attached to the stereotaxic apparatus (David Kopf Instruments, Tugunga, Calif.) in a prone position. Coaxial electrodes 0.5 mm in diameter (Rhodes Medical Instruments, Woodland Hills, Calif.) were placed in the posterior hypothalamus using de Groot’s coordinates: anteroposterior 5.0, lateral 1. O, and dorsoventral-2.5 (11). Electrodes were concluded to be positioned correctly when stimulation with a 0.25-mA current (frequency 90/s, pulse width 1 ms) for 10 s increased systolic pressure by more than 20 mmHg. After some experiments the rat’s brain was removed to verify histologically that the electrode tip was in the posterior hypothalamus, medial to the mamillothalamic tract and lateral to the third ventricle; in front of it was the dorsomedial hypothalamic nucleus and behind the premamillary and supramamillary nuclei; dorsal to it was the nucleus reuniens thalami and ventrally the dorsal premamillary nucleus (11). During experiments body temperature was kept constant at 37 C by a rectal thermistor probe connected to a heating pad through a temperature controller(Yellow Springs Instruments Co., Yellow Springs, Ohio), and the aortic catheter was filled with dilute heparin solution (ZOO U/ml) to minimize blood clotting. Phasic arterial pressure was monitored continuously by connecting the aortic catheter to a pressure transducer with low-volume displacement (Statham P23Gb). Heart rate was recorded simultaneously with a biotachometer(Gould Inc., Cleveland, Ohio) triggered by the phasic pressure signal from the transducer. For electrical stimulation hypothalamic electrodes were connected to a solid-state square-pulse stimulator through a constant-current unit (Grass Medical Instruments, Quincy, Mass.) and except when stated otherwise, a current strength of 0.25 mA was routinely used. All drugs were injected through the jugular vein catheter (4) with doses expressed as weight of the respective salt injected per rat. The drugs used were 1, l-dimethyl-4-phenylpiperazinium iodide (DMPP), guanethidine sulfate (Ismelin), norepinephrine bitartrate (Levophed), pentolinium tartrate(Ansolysen), phentolamine mesylate(Regi tine), propranolol hydrochloride (Inderal), and vasopressin (Pitressin). Antagonists were injected in divided. doses until there was no further inhibition of pressor responses to hypothalamic stimulation at 0.25