Characteristics of membrane current induced by excitory amino acid receptors and the acting way of L-SOP
- Received Date: 2008-07-08
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Key words:
- Xenopus oocytes /
- mRNA /
- excitory amino acid /
- ionic glutamate receprots /
- metabotropic glutamate receptors
Abstract: Objective: To study the characters of membrane current of types of excitory amino acide and the acting way of TypeⅢmGluR(metabotropic glutamate receptor) agonist—L-SOP among them. Methods: A total receptor RNA was isolated from adult rat brain by acid guanidnium thiocyanate-phenol-chloroform(AGPC) method,mRNA was isolated from the total RNA by oligo(dT)-cellu- cose chromatography,and was then micro-injected into Xenopus oocytes to express,through a two-microeleetrode voltage clamp tech- nique.The ooeytes were refused with varieties of types of excitory amino acid. Results: 100μM KA(kainate) (ionic glutamate recep- tor) induced first a peak current and then a slowly descending current,which desentized at last.The mean maintained time was 37.57 min.2μM QA(quisqualate) (TYPEⅠmGluR) induced regulary calcium oscillation with a maintained time of (6.72±1.33) min. Both of the maintained time were shortened the agonist concentration increased.0.8 mM L-SOP of TYPEⅢmGluR agonist induced a kind of disciplinary oscillation with a maintained time of (20.17±8.47) min which was also shortened with an increasing concentra- tion,while the oscillation coule be antagonized by TYPEⅠmGluR antagonist—L-AP3. Conclusion:: Each of these three types of gluta- mate amino acid receptors has its speuniquecial current mode when irritated;L-SOP is not only an agonist of TYPEⅢmGluR,but also a weak agonist of TYPEⅠ,that is,its acting way of producing oscillation is through TYPEⅠreceptor.
Citation: | ZHANG Jun, WANG Hui, JIN Xing. Characteristics of membrane current induced by excitory amino acid receptors and the acting way of L-SOP[J]. Journal of Pharmaceutical Practice and Service, 2008, (4): 258-260,296. |