scholarly journals The regulation of ATP-sensitive K+ channel activity in intact and permeabilized rat ventricular myocytes.

1990 ◽  
Vol 423 (1) ◽  
pp. 91-110 ◽  
Author(s):  
C G Nichols ◽  
W J Lederer
Keyword(s):  
Ventricular Myocytes ◽  
K Channel ◽  
Channel Activity ◽  
Rat Ventricular Myocytes

Intracellular ADP-ribose inhibits ATP-sensitive K+ channels in rat ventricular myocytes

1996 ◽  
Vol 271 (2) ◽  
pp. C464-C468 ◽  
Author(s):  
Y. G. Kwak ◽  
S. K. Park ◽  
U. H. Kim ◽  
M. K. Han ◽  
J. S. Eun ◽  
...  
Keyword(s):  
Single Channel ◽  
Ventricular Myocytes ◽  
Physiological Role ◽  
Hill Coefficient ◽  
K Channel ◽  
Channel Activity ◽  
Rat Ventricular Myocytes ◽  
Cyclic Adp Ribose ◽  
The Hill

Cyclic ADP-ribose (cADPR), an NAD metabolite, has been shown to be a messenger for Ca2+ mobilization from intracellular Ca2+ stores. However, the physiological role of ADP-ribose (ADPR), another metabolite of NAD, is not known. We examined the effects of cADPR and ADPR on the ATP-sensitive K+ channel (KATP) activity in rat ventricular myocytes by use of the inside-out patch-clamp configuration. ADPR, but not cADPR, inhibited the channel activity at micromolar range with an inhibitor constant (Ki) of 38.4 microM. The Hill coefficient was 0.9. ATP inhibited the K+ channel with a Ki of 77.8 microM, and the Hill coefficient was 1.8. Single-channel conductance was not affected by ADPR. These findings strongly suggest that ADPR may act as a regulator of KATP channel activity.

Biophysical properties of two types of ATP-sensitive K+ channel in rat ventricular myocytes

Heart Rhythm ◽  
2005 ◽  
Vol 2 (5) ◽  
pp. S215
Author(s):  
Adonis Zhi-Yang Wu ◽  
Ming Wei Lin ◽  
Ruey J. Sung ◽  
Sheng Nan Wu
Keyword(s):  
Ventricular Myocytes ◽  
K Channel ◽  
Biophysical Properties ◽  
Rat Ventricular Myocytes

Development of inwardly rectifying K+ channel family in rat ventricular myocytes

1997 ◽  
Vol 272 (4) ◽  
pp. H1741-H1750 ◽  
Author(s):  
L. H. Xie ◽  
M. Takano ◽  
A. Noma
Keyword(s):  
Single Channel ◽  
Ventricular Myocytes ◽  
K Channel ◽  
Resting Membrane Potential ◽  
Patch Clamp Technique ◽  
Open Probability ◽  
Rat Ventricular Myocytes ◽  
Adult Rat ◽  
K Current ◽  
Inwardly Rectifying

The ATP-sensitive K+ current (I(K,ATP)), the inward rectifier K+ current (I(K1)), and the acetylcholine-activated K+ current (I(K,ACh)) were recorded in fetal, neonatal, and adult rat ventricular myocytes using the patch-clamp technique. The density (pA/pF) of I(K1) increased from gestation day 10 through neonatal day 1 and then decreased after neonatal day 30. The density of I(K,ATP) activated maximally by metabolic inhibition changed in parallel with the I(K1) density, and the density of I(K,ATP) channel distribution was 1.3 times higher than that of I(K1) throughout the development. We failed to observe developmental changes in the single-channel conductance and the mean open time of I(K1) and I(K,ATP) channels. However, the open probability of the I(K,ATP) channel was lower in fetuses, and the sensitivity to ATP was highest in 1-day neonates. I(K,ACh) were present in the ventricle at all stages of development but at a much lower density than in atrium. The relationship between the resting membrane potential and the development of the inwardly rectifying K-channel family is discussed.

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