血管内皮舒张因子对豚鼠耳蜗功能的影响

目的 探讨血管内皮性一氧化氮合酶(endothelial nitric oxide synthase,eNOS)对耳蜗电位的影响.方法 健康豚鼠100只,随机等分为10组:①人工外淋巴液组;②L-精氨酸组;③Ca2+-ATP酶抑制剂组;④Ca2+-ATP酶抑制剂+L-精氨酸组;⑤Ca2+-ATP酶抑制剂+环磷酸鸟苷(c...

Effects of blood circulation on cochlear microcirculation in the cochlea of guinea pigs

OBJECTIVE To study the cochlear microcirculation effects of endothelial nitric oxide synthase（eNOS）of guinea pigs.METHODS Total 100 guinea pigs were divided into 10 groups as follows： ①artificial perilymph;②Ca2＋-ATPase inhibitor;③ L-arginine;④Ca2＋-ATPase inhibitor＋L-arginine;⑤Ca2＋ATPase inhibitor＋cGMP;⑥Ca2＋-ATPase inhibitor＋Larginine＋Non-selective NOS inhibitor;⑦nNOS inhibitor;⑧nNOS inhibitor＋Ca2＋-ATPase inhibitor;⑨ nNOS inhibitor＋Ca2＋-ATPase inhibitor＋L-arginine;⑩ nNOS inhibitor＋Ca2＋-ATPase inhibitor＋L-arginine＋eNOS inhibitor.Perilymphs of guinea pig were perfused with the drugs mentioned above at a rate of 2.5 μl/min for 2 hours.The compound action potential（CAP）was evoked by click,and the cochlea microphnics（CM）evoked by tone burst（1 kHz,rise and fall 2 ms,and plateau 20 ms）.The CAP and CM were recorded from the round window（RM） every 30 minutes.RESULTS The average threshold shift of CAP after perfusing Ca2＋-ATPase inhibitor was 28.5 dB SPL,and its improvement by L-arginine in group 4 was 9 dB SPL,similar to group 5.The threshold shift of CAP in group 8 was 43 dB SPL,and additional improvement of 7 dB SPL showed out after L-arginine added.Compared with group 9,more 6 dB SPL of improvement was got in group 10 after eNOS inhibitor added which has no obvious differences with group 8.Immunohistochemical results showed that L-arginine can improve the eNOS expression on cochlear striae vascularis.CONCLUSION ENOS can regulate cochlear microcirculation by adjusting contract and dilation of small artery on cochlear striae vascularis.