The Journal of General Physiology
Axon Instruments microelectrode amplifiers
  Home | Help | Feedback | Subscriptions | Archive | Search | Table of Contents
This Article
Right arrow PDF (Full Text)
Right arrow Alert me when this article is cited
Right arrow Citation Map
Services
Right arrow Email this article
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new content in the JGP
Right arrow Download to citation manager
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via CrossRef
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Dubinsky, J. M.
Right arrow Articles by Oxford, G. S.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Dubinsky, J. M.
Right arrow Articles by Oxford, G. S.
Social Bookmarking
Add to CiteULike   Add to Complore   Add to Connotea   Add to Del.icio.us   Add to Digg   Add to Reddit   Add to Technorati  
What's this?

The Journal of General Physiology, Vol 83, 309-339, Copyright © 1984 by The Rockefeller University Press

ARTICLES

Ionic currents in two strains of rat anterior pituitary tumor cells

JM Dubinsky and GS Oxford

The ionic conductance mechanisms underlying action potential behavior in GH3 and GH4/C1 rat pituitary tumor cell lines were identified and characterized using a patch electrode voltage-clamp technique. Voltage- dependent sodium, calcium, and potassium currents and calcium-activated potassium currents were present in the GH3 cells. GH4/C1 cells possess much less sodium current, less voltage-dependent potassium current, and comparable amounts of calcium current. Voltage-dependent inward sodium current activated and inactivated rapidly and was blocked by tetrodotoxin. A slower-activating voltage-dependent inward calcium current was blocked by cobalt, manganese, nickel, zinc, or cadmium. Barium was substituted for calcium as the inward current carrier. Calcium tail currents decay with two exponential components. The rate constant for the slower component is voltage dependent, while the faster rate constant is independent of voltage. An analysis of tail current envelopes under conditions of controlled ionic gradients suggests that much of the apparent decline of calcium currents arises from an opposing outward current of low cationic selectivity. Voltage- dependent outward potassium current activated rapidly and inactivated slowly. A second outward current, the calcium-activated potassium current, activated slowly and did not appear to reach steady state with 185-ms voltage pulses. This slowly activating outward current is sensitive to external cobalt and cadmium and to the internal concentration of calcium. Tetraethylammonium and 4-aminopyridine block the majority of these outward currents. Our studies reveal a variety of macroscopic ionic currents that could play a role in the initiation and short-term maintenance of hormone secretion, but suggest that sodium channels probably do not make a major contribution.
Add to CiteULike CiteULike   Add to Complore Complore   Add to Connotea Connotea   Add to Del.icio.us Del.icio.us   Add to Digg Digg   Add to Reddit Reddit   Add to Technorati Technorati    What's this?


This article has been cited by other articles:


Home page
 Anesth. Analg.Home page
K. Sugimoto, I. Kissin, and G. Strichartz
A High Concentration of Resiniferatoxin Inhibits Ion Channel Function in Clonal Neuroendocrine Cells
Anesth. Analg., July 1, 2008; 107(1): 318 - 324.
[Abstract] [Full Text] [PDF]

Home page
 EndocrinologyHome page
S.-K. Yang, H. C. Parkington, A. D. Blake, D. J. Keating, and C. Chen
Somatostatin Increases Voltage-Gated K+ Currents in GH3 Cells through Activation of Multiple Somatostatin Receptors
Endocrinology, November 1, 2005; 146(11): 4975 - 4984.
[Abstract] [Full Text] [PDF]

Home page
 Mol. Endocrinol.Home page
F. Van Goor, D. Zivadinovic, and S. S. Stojilkovic
Differential Expression of Ionic Channels in Rat Anterior Pituitary Cells
Mol. Endocrinol., July 1, 2001; 15(7): 1222 - 1236.
[Abstract] [Full Text] [PDF]

Home page
 Am. J. Physiol. Cell Physiol.Home page
D. D. Denson, X. Wang, R. T. Worrell, and D. C. Eaton
Effects of fatty acids on BK channels in GH3 cells
Am J Physiol Cell Physiol, October 1, 2000; 279(4): C1211 - C1219.
[Abstract] [Full Text] [PDF]

Home page
 Mol. Pharmacol.Home page
Z. Xiong, C. Bukusoglu, and G. R. Strichartz
Local Anesthetics Inhibit the G Protein-Mediated Modulation of K+ and Ca++ Currents in Anterior Pituitary Cells
Mol. Pharmacol., January 1, 1999; 55(1): 150 - 158.
[Abstract] [Full Text]

Home page
 Am. J. Physiol. Cell Physiol.Home page
D. D. Denson, R. T. Worrell, P. Middleton, and D. C. Eaton
Ca2+ sensitivity of BK channels in GH3 cells involves cytosolic phospholipase A2
Am J Physiol Cell Physiol, January 1, 1999; 276(1): C201 - C209.
[Abstract] [Full Text] [PDF]

Home page
 J. Biol. Chem.Home page
A. Lachowicz, F. Van Goor, A. C. Katzur, G. Bonhomme, and S. S. Stojilkovic
Uncoupling of Calcium Mobilization and Entry Pathways in Endothelin-stimulated Pituitary Lactotrophs
J. Biol. Chem., November 7, 1997; 272(45): 28308 - 28314.
[Abstract] [Full Text] [PDF]

Home page
 J. Biol. Chem.Home page
R. Peri, D. J. Triggle, and S. Singh
Regulation of L-type Calcium Channels in Pituitary GH4C1 Cells by Depolarization
J. Biol. Chem., August 17, 2001; 276(34): 31667 - 31673.
[Abstract] [Full Text] [PDF]

Home page
 Am. J. Physiol. Cell Physiol.Home page
R. I. Fonteriz, C. Villalobos, and J. Garcia-Sancho
An extracellular sulfhydryl group modulates background Na+ conductance and cytosolic Ca2+ in pituitary cells
Am J Physiol Cell Physiol, April 1, 2002; 282(4): C864 - C872.
[Abstract] [Full Text] [PDF]


  Home | Help | Feedback | Subscriptions | Archive | Search | Table of Contents