【摘要】 本工作探查了28只家兔延髓腹侧面化学敏感区的定位以及该区在机体对高 CO₂通气反应中的作用。用 pH 值为7.0、7.34和8.0的人工脑脊液滤纸敷贴在延髓腹侧表面观察通气变化。在锥体外方、第 Ⅶ一Ⅺ 对脑神经根部内侧和舌下神经根内侧两个区域用 pH7.0的滤纸敷贴时可使通气增加。反之,贴以浸有 pH 8.0的滤纸时可使通气减小。因此分别将此两区称为头端（R）和尾端（C）化学敏感区。在舌下神经根部上方,在 R 区和 C 区之间敷贴不同 pH 的滤纸则无通气变化。此区称为中间区（Ⅰ区）。PH7.34的滤纸敷贴以上三区均无通气变化。完整动物用 2%普鲁卡因麻醉 R 区和 C 区后,高 CO₂仍能引起通气增加,麻醉Ⅰ区后,高 CO₂引起通气减少。切断双侧颈动脉窦神经的动物,用2%普鲁卡因麻醉 R 区和 C 区,高 CO₂亦导致通气减少;麻醉Ⅰ区,则呼吸停止。上述结果表明,家兔延髓腹侧面存在着对称的化学敏感区。在机体对高 CO₂的通气反应中,Ⅰ区和 R、C 区都起着一定的作用。更多还原

【Abstract】 Experiments were performed on 28 rabbits anaesthetized with chloralose-ure-thane.Filter paper of 1.5mm~2 moistened with mock cerebrospinal fluid of pH7.0,7.34 or 8.0 was placed on different parts of the ventral medullary surface andthe resultant respiratory effects were observed.Topical application of acid C.S.F.to an area at the level between the pyramid and the roots of the seventh to tenthcranial nerves(the R area),or to an area medial to the root of the hypoglossal nerve(the C area),led to an increase in V_t,while application of alkaline C.S.F.to thesechemosensitive areas diminished V_t.The intermediate areas(theⅠarea)betweenthe R and C areas have no chemosensitivity.In the intact animals,after bilateralapplication of 2% procaine to both R and C areas hyperventilation response tohypercapnia could still be elicited,while application of procaine to Ⅰ areas,onlyhypoventilation response was resulted.In bilateral sinus denervated animals,af-ter applying procaine to R and C areas,hypercapnia could elicite hypoventilationonly,furthermore application of procaine toⅠareas led to apnea.These resultsdemonstrated that in the rabbit there are chemosensitive areas at the ventral sur-face of the medulla.The R and C areas,as well asⅠareas play important rolesin mediating the ventilatory response to hypercapnia.更多还原