大鼠颈动脉体球细胞缺氧时膜电位变化与球细胞大小的关系

RELATIONSHIP BETWEEN REACTION OF MEMBRANE POTENTIAL AND SIZE OF GLOMUS CELLS IN RAT CAROTID BODY DURING HYPOXIA

用细胞内记录法测定了８５个分离培养的大鼠颈动脉体球细胞的膜电位，并由显微照相法记录球细胞的形态进而以测微器测量球细胞的直径。由连二亚硫酸钠（Ｎａ２Ｓ２Ｏ４）造成缺氧（ＰＯ２，１．３－８．０ｋＰａ）。不同直径的球细胞对缺氧有两种不同反应：直径为８．０４±１．０９μｍ的球细胞对缺氧的反应均为去极化，直径为１４．３８±４．２１μｍ的球细胞对缺氧反应为超极化。因此似可认为，球细胞存在功能不同的亚型。缺氧程度不同对球细胞膜电位的改变也有一定影响，缺氧程度严重可使小型球细胞的去极化程度增加，但缺氧程度的高低不能改变两型球细胞对缺氧反应的固有型式。

The membrane potentials(Em) of 85 cultured isolated glomus cells were measured by intracellular recording.The shapes of glomus cells were recorded by microscopic photograph and the cell diameter was measured by micrometer enlarger. The glomus cells with different diameters exhibited two distinct responses to hypoxia.The glomus cells with diameter shorter than 10μm were depolarized in response to hypoxia, while the cells with diameter over 10μm were hyperpolarized during hypoxia. Thus,it is sugested that glomus cells may be divided into two functionally different subtypes. Although the smaller glomus cells depolarized more seriously under extreme hypoxia, the degree of hypoxia could not change the original response pattern of glomus cells to hypoxia.