NDLI: Potassium efflux triggered by P2Y purinoceptor activation in cultured pituicytes

Content Provider	Springer Nature Link
Author	Troadec, J.D. Thirion, S. Petturiti, D. Poujeol, P.
Copyright Year	2000
Abstract	We have previously investigated the effects of extracellular ATP on the concentration of free cytosolic calcium ([Ca2+]i) from rat cultured neurohypophysial astrocytes (pituicytes). We demonstrated that ATP acts via a P2Y receptor to increase [Ca2+]i. In the present study, we examine the effect of ATP on K+ efflux using 86Rb+ as an isotopic tracer, in order to characterize the possible presence of a Ca2+-activated K+ conductance and to establish the implications of pituicytes in the regulation of stimulus–secretion coupling. ATP evoked an increase in 86Rb+ efflux from cultured pituicytes. This effect was Ca2+ dependent, as indicated by the unresponsiveness of cells loaded with BAPTA/AM (20 µM). Furthermore, the effect of ATP was mimicked by 2-methylthio-adenosine-5′-triphosphate (2MeSATP), a P2 purinoceptor agonist, and abolished by Reactive Blue 2 (RB-2), a selective P2Y antagonist, implying a role for the P2Y purinoreceptor. A pharmacological study revealed that Ba2+ and tetraethylammonium (TEA), two inhibitors of K+ channels, both strongly reduced the ATP-stimulated 86Rb+ efflux. In addition, the effect of ATP was modulated by different peptidic toxins. Apamin (100 nM), an inhibitor of the small-conductance Ca2+-activated K+ channels, partly blocked ATP-induced 86Rb+ efflux. Leiurus quinquestriatus hebraeus (LQH) scorpion venom (20 µg/ml) and Buthus tamulus (BT) scorpion venom (20–200 µg/ml) inhibited ATP-induced 86Rb+ efflux. The specificity of the effects of the crude venoms was checked using charybdotoxin (100 nM) and iberiotoxin (1 µM), which are the active toxins extracted from the LQH and BT venoms, respectively. These data indicate the involvement of several types of Ca2+-activated K+ channels in the ATP-dependent K+ efflux, and lead to the proposal that, in the neurohypophysis, extracellular ATP released by nerve terminals may act directly on the pituicytes and induce a K+ efflux via a P2Y purinoreceptor.
Starting Page	770
Ending Page	777
Page Count	8
File Format	PDF
ISSN	00316768
Journal	Pflügers Archiv
Volume Number	440
Issue Number	5
e-ISSN	14322013
Language	English
Publisher	Springer-Verlag
Publisher Date	2000-06-27
Publisher Place	Berlin, Heidelberg
Access Restriction	One Nation One Subscription (ONOS)
Subject Keyword	Human Physiology
Content Type	Text
Resource Type	Article
Subject	Physiology Physiology (medical) Clinical Biochemistry

Sl.	Authority	Responsibilities	Communication Details
1	Ministry of Education (GoI), Department of Higher Education	Sanctioning Authority	https://www.education.gov.in/ict-initiatives
2	Indian Institute of Technology Kharagpur	Host Institute of the Project: The host institute of the project is responsible for providing infrastructure support and hosting the project	https://www.iitkgp.ac.in
3	National Digital Library of India Office, Indian Institute of Technology Kharagpur	The administrative and infrastructural headquarters of the project	Dr. B. Sutradhar bsutra@ndl.gov.in
4	Project PI / Joint PI	Principal Investigator and Joint Principal Investigators of the project	Dr. B. Sutradhar bsutra@ndl.gov.in Prof. Saswat Chakrabarti will be added soon
5	Website/Portal (Helpdesk)	Queries regarding NDLI and its services	support@ndl.gov.in
6	Contents and Copyright Issues	Queries related to content curation and copyright issues	content@ndl.gov.in
7	National Digital Library of India Club (NDLI Club)	Queries related to NDLI Club formation, support, user awareness program, seminar/symposium, collaboration, social media, promotion, and outreach	clubsupport@ndl.gov.in
8	Digital Preservation Centre (DPC)	Assistance with digitizing and archiving copyright-free printed books	dpc@ndl.gov.in
9	IDR Setup or Support	Queries related to establishment and support of Institutional Digital Repository (IDR) and IDR workshops	idr@ndl.gov.in

ATP acting on P2Y receptors triggers calcium mobilization in primary cultures of rat neurohypophysial astrocytes (pituicytes)

Luminal ATP-induced contraction of rabbit pulmonary arteries and role of purinoceptors in the regulation of pulmonary arterial pressure

Recombinant Kv1.3 potassium channels stabilize tonic firing of cultured rat hippocampal neurons

Activation of hEAG1 potassium channels by arachidonic acid

P2X purinoceptors and sensory transmission

Regulatory mechanisms underlying the modulation of GIRK1/GIRK4 heteromeric channels by P2Y receptors

Functions of neuronal P2Y receptors

A large-conductance voltage-dependent potassium channel in cultured pig articular chondrocytes

Altered gating of HERG potassium channels by cobalt and lanthanum

Potassium efflux triggered by P2Y purinoceptor activation in cultured pituicytes

Similar Documents

ATP acting on P2Y receptors triggers calcium mobilization in primary cultures of rat neurohypophysial astrocytes (pituicytes)

Luminal ATP-induced contraction of rabbit pulmonary arteries and role of purinoceptors in the regulation of pulmonary arterial pressure

Recombinant Kv1.3 potassium channels stabilize tonic firing of cultured rat hippocampal neurons

Activation of hEAG1 potassium channels by arachidonic acid

P2X purinoceptors and sensory transmission

Regulatory mechanisms underlying the modulation of GIRK1/GIRK4 heteromeric channels by P2Y receptors

Functions of neuronal P2Y receptors

A large-conductance voltage-dependent potassium channel in cultured pig articular chondrocytes

Altered gating of HERG potassium channels by cobalt and lanthanum

Potassium efflux triggered by P2Y purinoceptor activation in cultured pituicytes