Note to users. If you're seeing this message, it means that your browser cannot find this page's style/presentation instructions -- or possibly that you are using a browser that does not support current Web standards. Find out more about why this message is appearing, and what you can do to make your experience of our site the best it can be.

Science 9 January 1970:
Vol. 167. no. 3915, pp. 182 - 184
DOI: 10.1126/science.167.3915.182
Prev | Table of Contents | Next

Articles

Adenohypophysial Transmembrane Potentials: Polarity Reversal by Elevated External Potassium Ion Concentration

J. V. Milligan 1 and Jacob Kraicer 1

1 Department of Physiology, Queen's University, Kingston, Ontario, Canada

Incubation of rat adenohypophyses in potassium ion of sufficient concentration to provoke the release of several of the adenohypophysial trophic hormones produces a reversed, positive transmembrane potential in more than half the cells. This finding is consistent with a process of "stimulus-secretion coupling" in which hypothalamic releasing factors act by selective depolarization of their "target" cells. The positive potentials may be due to a prolonged preferential permeability to calcium ions triggered by an initial depolarization of the cell membrane to a threshold value by increased external potassium ion.


THIS ARTICLE HAS BEEN CITED BY OTHER ARTICLES:
Cell Communication, Calcium Ion, and Cyclic Adenosine Monophosphate.
H. Rasmussen (1970)
Science 170, 404-412
   Abstract »    PDF »


To Advertise     Find Products

Science. ISSN 0036-8075 (print), 1095-9203 (online)