多粘菌素B对豚鼠内耳碳酸酐酶活性的影响

Influence of Polymyxin B on the Activity of Carbonic Anhydrase in the Inner Ear of Guinea Pig

为了解多粘菌素Ｂ（ＰＢ）对内耳碳酸酐酶（ＣＡＨ）的影响，用Ｈａｎｓｓｏｎ法和Ｙｏｋｏｔａ法观察豚鼠鼓室注射生理盐水或ＰＢ１万Ｕ／ｍｌ后内耳ＣＡＨ的定位。结果发现生理盐水组豚鼠内耳ＣＡＨ分布广泛，血管纹、内外毛细胞表现为极强阳性，前庭暗细胞表现为强阳性。ＰＢ组内耳ＣＡＨ活性普遍减低，电镜下外毛细胞内ＣＡＨ反应产物几乎消失，并且出现细胞水肿。推测ＰＢ破坏细胞膜的通透性后影响ＣＡＨ的活性。

Fourty albino guinea pigs were divided into two groups at random, they were injected with 0.9% natrii chloride or 10 000 U/ml polymyxin B 0.1 ml for five days. The activity of carbonic anhydrase(CAH) in the inner ear was observed with LM and TEM. The result is that CAH is widely distributed in the inner ear in the first group. Very strong reaction products were found in outer hair cells(OHC), inner hair cells(IHC), and marginal cells(MG) of stria vascular. Strong reaction products were found in dark cells(DC) of vestibule. Weaker CAH activity were found in the second group than in the first. OHC showed degeneration and almost no reaction products by TEM observation. It is concluded that polymyxin B could influence CAH activity of labyrinth and result in more severe ototoxicity.