Maeda M, Nakai M, Krieger A J, Sapru H N
Department of Physiology, Osaka City University Medical School, Abeno, Japan.
Brain Res. 1990 Jun 18;520(1-2):255-61. doi: 10.1016/0006-8993(90)91713-q.
In anesthetized (chloralose and urethane), paralyzed and artificially ventilated rats, the neurons in the nucleus tractus solitarius (NTS) were chemically stimulated by microinjections of L-glutamate and the cerebral blood flow (CBF) was determined using a combination of labeled microspheres (either 57Co, 113Sn and 46Sc or 141Ce, 85Sr and 46Sc). Unilateral chemical stimulation of the NTS (n = 14) decreased CBF significantly in most brain areas. The decrease in CBF was not due to the decrease in arterial blood pressure (ABP) because the CBF of the whole cerebral cortex during the chemical stimulation of the NTS was significantly smaller (P less than 0.05) than the CBF during controlled hemorrhagic hypotension (n = 10). In another group of rats (n = 6), moderate hypertension was induced by blood transfusion. Unilateral chemical stimulation of the NTS in these rats decreased ABP but it remained within normotensive range. A significant (P less than 0.05) decrease in CBF (from 62 +/- 28 (mean +/- S.D.) to 48 +/- 23 ml.min-1.(100 g)-1) and increase in cerebrovascular resistance (from 1.9 +/- 1.2 to 2.6 +/- 1.2 mm Hg per [ml.min-1.(100 g)-1]) was observed in the whole cerebral cortex of these rats. Chemical stimulation of the NTS did not affect the reactivity of the cerebral vessels to hypercapnea (n = 5). These results suggest that the cell bodies within the NTS may play a role in the control of cerebral circulation.
在使用水合氯醛和氨基甲酸乙酯麻醉、麻痹并进行人工通气的大鼠中，通过微量注射L-谷氨酸对孤束核（NTS）中的神经元进行化学刺激，并使用标记微球组合（57Co、113Sn和46Sc或141Ce、85Sr和46Sc）来测定脑血流量（CBF）。对NTS进行单侧化学刺激（n = 14）可使大多数脑区的CBF显著降低。CBF的降低并非由于动脉血压（ABP）的降低，因为在NTS化学刺激期间全脑皮质的CBF显著小于（P < 0.05）控制性出血性低血压期间的CBF（n = 10）。在另一组大鼠（n = 6）中，通过输血诱导中度高血压。对这些大鼠的NTS进行单侧化学刺激可降低ABP，但仍保持在正常血压范围内。在这些大鼠的全脑皮质中观察到CBF显著（P < 0.05）降低（从62 ± 28（平均值 ± 标准差）降至48 ± 23 ml·min-1·(100 g)-1），脑血管阻力增加（从1.9 ± 1.2增至2.6 ± 1.2 mmHg/[ml·min-1·(100 g)-1]）。对NTS的化学刺激不影响脑血管对高碳酸血症的反应性（n = 5）。这些结果表明，NTS内的细胞体可能在脑循环控制中发挥作用。
