STUDY OF ELECTROCHEMISTRY AND OSMOTIC RELATIONSHIPS OF COCHLEAR FLUIDS IN NEONATAL RAT AT TIME OF DEVELOPMENT OF ENDOCOCHLEAR POTENTIAL
STUDY OF ELECTROCHEMISTRY AND OSMOTIC RELATIONSHIPS OF COCHLEAR FLUIDS IN NEONATAL RAT AT TIME OF DEVELOPMENT OF ENDOCOCHLEAR POTENTIAL
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DOI：
10.1113/jphysiol.1971.sp009354
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发表时间：
1971-01-01
影响因子：
5.5
通讯作者：
WARREN, RL
中科院分区：
文献类型：
--
作者：
BOSHER, SK;WARREN, RL
1.本文研究了大鼠生后第8天至第18天耳蜗内电位的变化。最初的电位很低，但在第11天和第16天之间其幅度迅速增加。在第13和第14天期间，增加速率约为1 mV/hr。耳蜗的三个匝几乎同时出现快速的电位增加。组织学检查显示耳蜗，包括Corti氏器和血管纹的毛细胞，在耳蜗内电位快速变化期之前已经完全成熟，除了Claudius细胞，其最终发育与该阶段的后半部分相一致.内淋巴钠浓度（平均1.0 m-当量/l）在研究的最早期达到了非常低的成人水平。钾和氯浓度略低于正常成人水平，这是由于此时存在一定程度的一般低渗透压。在耳蜗内电位快速上升阶段，内淋巴离子浓度保持不变.结果表明，耳蜗内淋巴离子成分和耳蜗电位在耳蜗发育过程中是独立和连续出现的.内淋巴、外淋巴和血清之间的渗透压无差异。因此，关于内耳液体的体内平衡的问题似乎并不因不寻常的流体动力学方面而复杂化。通过腹腔内注射水或高渗甘油产生的体液渗透压的改变伴随着内耳液渗透压的同时变化。因此，限制内淋巴空间的膜的某些部分被认为是水可自由渗透的。调查没有提供进一步的信息耳蜗内电位的性质，虽然在耳蜗管膜的电阻增加被认为是负责其外观。这一时期的时间关系支持这样的概念，即电势是机电转换过程的基本特征。
1. Changes in the endocochlear potential between the 8th and 18th days after birth were investigated in the rat. Initially the potential was low but its magnitude increased rapidly between the 11th and 16th day. During the 13th and 14th days the rate of increase was approximately 1 mV/hr.2. The rapid potential increase arose virtually simultaneously in all three turns of the cochlea.3. Histological examination revealed the cochlea, including the hair cells of Corti's organ and the stria vascularis, to be fully mature before the period of rapid change in the endocochlear potential, apart from the cells of Claudius, whose final development coincided with the latter part of this phase.4. The endolymphatic sodium concentration (average 1·0 m‐equiv/l.) had attained the very low adult level in the earliest period studied. The potassium and chloride concentrations were slightly below the normal adult levels, the result of some degree of general hypo‐osmolality present at this time.5. The endolymphatic ionic concentrations remained unchanged during the phase of rapid increase in the endocochlear potential.6. The findings thus indicate that the distinctive endolymphatic ionic composition and the endocochlear potential arise largely independently and in succession during cochlear maturation.7. No differences in osmotic pressure were demonstrated between endolymph, perilymph and serum. The problems concerning the homoeostasis of the inner ear fluids do not consequently seem to be complicated by unusual hydrodynamic aspects.8. Alterations in body fluid osmolality, produced by intraperitoneal injection of water or hypertonic glycerol, were accompanied by simultaneous changes in the osmotic pressures of the inner ear fluids. Some portion of the membranes bounding the endolymphatic space is therefore considered to be freely permeable to water.9. The investigations provide no further information about the nature of the endocochlear potential, although an increase in the electrical resistance of the cochlear duct membranes is thought responsible for its appearance. The time relationships of this period support the concept that the potential is an essential feature of the mechano‐electric transduction process.