n/a
Abstract Title:

[Thiol reagent thimerosal-induced Ca2+ mobilization in isolated guinea pig cochlear outer hair cells].

Abstract Source:

Zhonghua Er Bi Yan Hou Ke Za Zhi. 2000 Jun ;35(3):192-5. PMID: 12768775

Abstract Author(s):

L Chen, S Jiang, W Yang, D Han, T Yuan, X Shan

Article Affiliation:

L Chen

Abstract:

OBJECTIVE: To understand mechanism of cochlear outer hair cells (OHCs) intracellular Ca2+ mobilization further.

METHODS: Intracellular calcium of isolated guinea pig was investigated using thimerosal, a--SH group oxidizing agent, and fura-2 fluorescence ratio imaging microscopy.

RESULTS: In the presence of thimerosal, intracellular Ca2+ concentrations ([Ca2+]i) of OHCs were elevated in a dose-dependent manner. Even in Ca(2+)-free medium, Ca2+ response was still induced. The effects of thimerosal on [Ca2+]i were completely blocked and reversed by (DTT). Neither 1-100 mumol/L ryanodine nor 5-20 mmol/L caffeine altered the effects of thimerosal. Pretreatment with pertussis toxin (PTX) for 30 min did not affect the thimerosal-induced increase in [Ca2+]i The increase in [Ca2+]i when Ca2+ was added during thimerosal application in Ca(2+)-free medium was almost completely blocked by 500 mol/L LaCl3, while nifedipine did not inhibit further increase in [Ca2+]i caused by thimerosal.

CONCLUSION: Oxidation of the -SH group of the OHC membrane can induce a Ca2+ release from intracellular Ca2+ stores, which are ryanodine- and caffeine-insensitive, and Ca2+ influx through non-specific Ca2+ channels, but not the nifedipine-sensitive Ca2+ Channels. The possible oxidation of--SH group gated Ca2+ channels in OHCs are worthy of further study.

Study Type : In Vitro Study
Additional Links
Problem Substances : Thimerosal : CK(618) : AC(0)

Print Options


Key Research Topics

Sayer Ji
Founder of GreenMedInfo.com

Subscribe to our informative Newsletter & get Nature's Evidence-Based Pharmacy

Our newsletter serves 500,000 with essential news, research & healthy tips, daily.

Download Now

500+ pages of Natural Medicine Alternatives and Information.

This website is for information purposes only. By providing the information contained herein we are not diagnosing, treating, curing, mitigating, or preventing any type of disease or medical condition. Before beginning any type of natural, integrative or conventional treatment regimen, it is advisable to seek the advice of a licensed healthcare professional.

© Copyright 2008-2021 GreenMedInfo.com, Journal Articles copyright of original owners, MeSH copyright NLM.