[Inhibition of salicylate on potassium channels in rat inferior colliculus neurons].

Abstract

OBJECTIVE:

To understand what role of the transient outward potassium channels and the delayed rectifier potassium channels play in the mechanism of salicylate-induced tinnitus.

METHODS:

The effects of salicylate on the transient outward potassium channels and the delayed rectifier potassium channels in freshly dissociated inferior colliculus neurons of rats were studied, using the whole-cell voltage clamp method.

RESULTS:

Salicylate blocked the transient outward potassium current (I(K(A and the delayed rectifier potassium current (I(K(DR in concentration-dependent manner (0.1-1 mmol/L). The IC50 values for the blocking action of salicylate on I(K(A)) and I(K(DR)) were 2.27 and 0.80 mmol/L, respectively. At a concentration of 1 mmol/L, salicylate did not shift the activation and inactivation curves of I(K(A)), but significantly shifted the activation and inactivation curves of I(K(DR)) negatively by approximately 11 mV and 24 mV.

CONCLUSIONS:

Salicylate inhibits both I(K(A)) and I(K(DR)) in rat inferior colliculus neurons but only significantly affects the activation and inactivation kinetics of I(K(DR)). Effects of I(K(A)) and I(K(DR)), especially I(K(DR)), by salicylate may play an important role in salicylate-induced tinnitus.

• Authors: Yan-xing Liu, Xue-pei Li, Jun-xiu Liu, Ge-ming Shi, Hong Lu, Chang-sheng Ma
• Journal: Zhonghua er bi yan hou tou jing wai ke za zhi = Chinese journal of otorhinolaryngology head and neck surgery (Zhonghua Er Bi Yan Hou Tou Jing Wai Ke Za Zhi) Vol. 40 Issue 11 Pg. 835-9 (Nov 2005) ISSN: 1673-0860 [Print] China
• PMID: 16408750 (Publication Type: English Abstract, Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Delayed Rectifier Potassium Channels
• Potassium Channels
• Salicylates

Topics

• Animals
• Delayed Rectifier Potassium Channels (drug effects)
• Inferior Colliculi (cytology, drug effects)
• Male
• Neurons (drug effects, physiology)
• Patch-Clamp Techniques
• Potassium Channels (drug effects, physiology)
• Rats
• Rats, Wistar
• Salicylates (pharmacology)