Potassium Channel Blockers Have Minimal Effect on Repolarization of Spontaneous Action Potentials in Rat Pituitary Lactotropes

1998 ◽  
Vol 68 (5) ◽  
pp. 297-311 ◽  
Author(s):  
Sethuraman Sankaranarayanan ◽  
Steven M. Simasko
Keyword(s):  
Potassium Channel ◽  
Action Potentials ◽  
Channel Blockers ◽  
Minimal Effect ◽  
Potassium Channel Blockers ◽  
Rat Pituitary ◽  
Spontaneous Action ◽  
Spontaneous Action Potentials

scholarly journals Action Potentials in Rhodnius Oocytes: Repolarization is Sensitive to Potassium Channel Blockers

1986 ◽  
Vol 126 (1) ◽  
pp. 119-132
Author(s):  
M. J. O'DONNELL
Keyword(s):  
Potassium Channel ◽  
Action Potentials ◽  
Potassium Conductance ◽  
Channel Blockers ◽  
Calcium Dependent ◽  
Outward Rectification ◽  
Current Voltage ◽  
Potassium Channel Blockers ◽  
Potassium Conductances ◽  
Voltage Dependent

Depolarization of Rhodnius oocytes evokes action potentials (APs) whose rising phase is calcium-dependent. The ionic basis for the repolarizing (i.e. falling) phase of the AP was examined. Addition of potassium channel blockers (tetraethylammonium, tetrabutylammonium, 4-aminopyridine, atropine) to the bathing saline increased the duration and overshoot of APs. Intracellular injection of tetraethyl ammonium had similar effects. These results suggest that a voltage-dependent potassium conductance normally contributes to repolarization. Repolarization does not require a chloride influx, because substitution of impermeant anions for chloride did not increase AP duration. AP duration and overshoot actually decreased progressively when chloride levels were reduced. Current/voltage curves show inward and outward rectification, properties often associated with potassium conductances. Outward rectification was largely blocked by external tetraethylammonium. Possible functions of the rectifying properties of the oocyte membrane are discussed.

Role of K+ Channels in Frequency Regulation of Spontaneous Action Potentials in Rat Pituitary GH3 Cells

2003 ◽  
Vol 78 (5) ◽  
pp. 260-269 ◽  
Author(s):  
Suk-Ho Lee ◽  
Eun Hae Lee ◽  
Shin Young Ryu ◽  
Hyewhon Rhim ◽  
Hye-Jung Baek ◽  
...  
Keyword(s):  
Action Potentials ◽  
Frequency Regulation ◽  
Rat Pituitary ◽  
Spontaneous Action ◽  
Spontaneous Action Potentials

Proteinase inhibitor homologues as potassium channel blockers

1994 ◽  
Vol 1 (4) ◽  
pp. 246-250 ◽  
Author(s):  
Jean-Marc Lancelin ◽  
Marie-Françoise Foray ◽  
Marc Poncin ◽  
Michelle Hollecker ◽  
Dominique Marion
Keyword(s):  
Potassium Channel ◽  
Proteinase Inhibitor ◽  
Channel Blockers ◽  
Potassium Channel Blockers
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