Effect of Phosphate Ions on Biophysical Properties of Rat Hepatocytes Endoplasmic Reticulum Potassium Channel

BACKGROUND AND OBJECTIVE: Rough endoplasmic reticulum is important organelle that plays a role in the regulation of a range of functions. Potassium channels in the endoplasmic reticulum membrane were recently reported that its physiological role is unknown. Hepatocyte endoplasmic reticulum is a rich...

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Autores principales:	H Sepehri, M Ashrafpour
Formato:	article
Lenguaje:	EN FA
Publicado:	Babol University of Medical Sciences 2012
Materias:	endoplasmic reticulum potassium channel phosphate ion Medicine R Medicine (General) R5-920
Acceso en línea:	https://doaj.org/article/83438f166fda4daeb95094989b01e40f
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spelling	oai:doaj.org-article:83438f166fda4daeb95094989b01e40f2021-11-10T08:53:33ZEffect of Phosphate Ions on Biophysical Properties of Rat Hepatocytes Endoplasmic Reticulum Potassium Channel1561-41072251-7170https://doaj.org/article/83438f166fda4daeb95094989b01e40f2012-11-01T00:00:00Zhttp://jbums.org/article-1-4237-en.htmlhttps://doaj.org/toc/1561-4107https://doaj.org/toc/2251-7170BACKGROUND AND OBJECTIVE: Rough endoplasmic reticulum is important organelle that plays a role in the regulation of a range of functions. Potassium channels in the endoplasmic reticulum membrane were recently reported that its physiological role is unknown. Hepatocyte endoplasmic reticulum is a rich source of glucose 6- phosphatase that is involved in the control of gluconeogenesis. Since phosphate ions are intra-luminal metabolites for this enzyme of endoplasmic reticulum thus, in this study, the effect of phosphate ions on potassium channel activity was studied.METHODS: Endoplasmic reticulum vesicles extraction was accomplished following liver excision in rats, homogenization and several stages of ultracentrifugation. Phosphatidylcholine was extracted from fresh egg yolk. Bilayer lipid membrane was formed in a 350 µm diameter aperture in between two chambers cis and trans contained 200/50 mMKCl solutions respectively, then vesicles were incorporated into bilayer lipid membrane. Ion channel activity was recorded by single channel recording technique both in control conditions and presence of phosphate ion in luminal face, next biophysical ion channel properties analyzed by Clampfit10 software.FINDINGS: Endoplasmic reticulum Potassium channel was 550 pS conductance and its activity changed as voltage dependent manner in voltage range of +30 to -40 mV, in this respect the open probability and the average unitary current in a voltage + 30 mV were 0.73 and 26 pA, respectively. However, at lower voltages, the channel activity was minimal. In the presence of 50 mM phosphate ion, mean unitary current and also channel open probability did not change significantly in different voltages compared to the control condition (p>0.05).CONCLUSION: Rat hepatocyte endoplasmic reticulum membranes has been a kind of potassium channel with voltage-dependent activity and it seems that its electrophysiological characteristics did not influenced by phosphate anion in luminal face.H Sepehri,M AshrafpourBabol University of Medical Sciencesarticleendoplasmic reticulumpotassium channelphosphate ionMedicineRMedicine (General)R5-920ENFAMajallah-i Dānishgāh-i ̒Ulūm-i Pizishkī-i Bābul, Vol 14, Iss 6, Pp 33-38 (2012)
institution	DOAJ
collection	DOAJ
language	EN FA
topic	endoplasmic reticulum potassium channel phosphate ion Medicine R Medicine (General) R5-920
spellingShingle	endoplasmic reticulum potassium channel phosphate ion Medicine R Medicine (General) R5-920 H Sepehri, M Ashrafpour Effect of Phosphate Ions on Biophysical Properties of Rat Hepatocytes Endoplasmic Reticulum Potassium Channel
description	BACKGROUND AND OBJECTIVE: Rough endoplasmic reticulum is important organelle that plays a role in the regulation of a range of functions. Potassium channels in the endoplasmic reticulum membrane were recently reported that its physiological role is unknown. Hepatocyte endoplasmic reticulum is a rich source of glucose 6- phosphatase that is involved in the control of gluconeogenesis. Since phosphate ions are intra-luminal metabolites for this enzyme of endoplasmic reticulum thus, in this study, the effect of phosphate ions on potassium channel activity was studied.METHODS: Endoplasmic reticulum vesicles extraction was accomplished following liver excision in rats, homogenization and several stages of ultracentrifugation. Phosphatidylcholine was extracted from fresh egg yolk. Bilayer lipid membrane was formed in a 350 µm diameter aperture in between two chambers cis and trans contained 200/50 mMKCl solutions respectively, then vesicles were incorporated into bilayer lipid membrane. Ion channel activity was recorded by single channel recording technique both in control conditions and presence of phosphate ion in luminal face, next biophysical ion channel properties analyzed by Clampfit10 software.FINDINGS: Endoplasmic reticulum Potassium channel was 550 pS conductance and its activity changed as voltage dependent manner in voltage range of +30 to -40 mV, in this respect the open probability and the average unitary current in a voltage + 30 mV were 0.73 and 26 pA, respectively. However, at lower voltages, the channel activity was minimal. In the presence of 50 mM phosphate ion, mean unitary current and also channel open probability did not change significantly in different voltages compared to the control condition (p>0.05).CONCLUSION: Rat hepatocyte endoplasmic reticulum membranes has been a kind of potassium channel with voltage-dependent activity and it seems that its electrophysiological characteristics did not influenced by phosphate anion in luminal face.
format	article
author	H Sepehri, M Ashrafpour
author_facet	H Sepehri, M Ashrafpour
author_sort	H Sepehri,
title	Effect of Phosphate Ions on Biophysical Properties of Rat Hepatocytes Endoplasmic Reticulum Potassium Channel
title_short	Effect of Phosphate Ions on Biophysical Properties of Rat Hepatocytes Endoplasmic Reticulum Potassium Channel
title_full	Effect of Phosphate Ions on Biophysical Properties of Rat Hepatocytes Endoplasmic Reticulum Potassium Channel
title_fullStr	Effect of Phosphate Ions on Biophysical Properties of Rat Hepatocytes Endoplasmic Reticulum Potassium Channel
title_full_unstemmed	Effect of Phosphate Ions on Biophysical Properties of Rat Hepatocytes Endoplasmic Reticulum Potassium Channel
title_sort	effect of phosphate ions on biophysical properties of rat hepatocytes endoplasmic reticulum potassium channel
publisher	Babol University of Medical Sciences
publishDate	2012
url	https://doaj.org/article/83438f166fda4daeb95094989b01e40f
work_keys_str_mv	AT hsepehri effectofphosphateionsonbiophysicalpropertiesofrathepatocytesendoplasmicreticulumpotassiumchannel AT mashrafpour effectofphosphateionsonbiophysicalpropertiesofrathepatocytesendoplasmicreticulumpotassiumchannel
_version_	1718440391594737664

Effect of Phosphate Ions on Biophysical Properties of Rat Hepatocytes Endoplasmic Reticulum Potassium Channel

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