腺苷对豚鼠耳蜗功能的影响

腺苷作为一种神经调质，能抑制多种递质的释放，发挥负反馈调节作用，用外淋巴灌流给药方法，观察了腺苷及其摄取抑制剂双嘧啶氨醇、受体拮抗剂茶 对豚鼠复合听神经动作电位、微音器电位、蜗内直流电位的影响。

EFFECTS OF ADENOSINE ON COCHLEAR FUNCTION IN GUINEA PIGS

As a neuromodulator, adenosine is able to decrease the release of most neurotransmittersand plays a role of negative feedback regulation. In the present experiment, the effects of adenosine, and its uptake inhibitor dipyridamole and antagonist theophylline on cochlear potentials were investigated by means of perilymphatic perfusion. 0. 01 mmol/L adenosine and dipyridamole was shown to suppress compound action potentials (CAP) and cochlear microphonics (CM). The amplitudes of CAP and CM were decreasedunder high sound intensity stimulation. The I/O function curve was shifted towardthe right and the N1 peak latency of CAP was prolonged. 1 mmol/L theophylline showed opposite effects. All these changes are reversible after washing out of the artifictal perilymphy. Normal endocochlear potentials (EP) and anoxia induced negative EP (N-EP) were not changed significantly, while the rapid response of EP to noise exposure, i. e. a rapid fall with onset of noise (EP-on) and a rapid increase with offset (EP-off), could be suppressed by adenosine. These results suggest that adenosine is an inhibitory neuromodulator subserving a negative feedback role in the regulation of cochlear function.