Adenohypophysial transmembrane potentials: polarity reversal by elevated external potassium ion concentration.
Science
; 167(3915): 182-4, 1970 Jan 09.
Article
in En
| MEDLINE
| ID: mdl-4902437
ABSTRACT
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.
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Database:
MEDLINE
Main subject:
Pituitary Gland
/
Potassium
/
Membrane Potentials
Limits:
Animals
Language:
En
Year:
1970
Type:
Article