Cholinergic agonists increase intracellular calcium concentration in guinea pig vestibular hair cells
10.3760/j.issn:0366-6999.2001.07.011
- VernacularTitle:胆碱能受体激动剂引起豚鼠离体前庭毛细胞内钙离子浓度升高
- Author:
Weiju HAN
1
;
Suzhen ZHANG
;
Dongyi HAN
;
Sichang JIANG
;
Weiyan YANG
Author Information
1. General Hospital of PLA
- Keywords:
vestibular hair cells;
calcium;
cholinergic receptors;
confocal microscopy
- From:
Chinese Medical Journal
2001;114(7):714-717
- CountryChina
- Language:Chinese
-
Abstract:
Abstract:Objective To better understand the cholinergic receptors in vestibular hair cells (VHC) and their subtypes, and to investigate the effects of cholinergic agonists on intracellular calcium concentration ([Ca2+]i ) in guinea pig VHCs.Methods VHCs were isolated from guinea pig crista ampullaris by enzymatic and mechanical methods. The effect of cholinergic agonists on [Ca2+]i was examined using laser scanning confocal microscopy and the Ca2+ sensitive dye Fluo-3.Results The results showed that the addition of acetylcholine (ACh) and carbachol (CCh), muscarnic and nicotinic agonists, induced [Ca2+]i increases in all the VHCs, whereas acetylcholine bromide (ACh-Br), a nicotinic agonist, induced the [Ca2+]i increase in only a small percentage of VHCs. The ACh or CCh-induced Ca2+ response could be partially suppressed by atropine. In the presence of 0.1?mmol/L atropine, the amplitudes of ACh or CCh-induced [Ca2+]i responses became significantly smaller than those in atropine free medium (P<0.01). Conclusions The results suggest the existence of cholinergic receptors in guinea pig VHCs. It is the muscarnic agonists rather than nicontic receptors that dominate [Ca2+]i variation. Atropine can suppress muscarnic agonist-induced Ca2+ responses.
