The Na + -activated K + channel contributes to K + efflux in Na + -loaded guinea-pig but not rat ventricular myocytes

2001 ◽  
Vol 442 (4) ◽  
pp. 595-602 ◽  
Author(s):  
Lawrence C. ◽  
Rodrigo G.
1996 ◽  
Vol 271 (2) ◽  
pp. C464-C468 ◽  
Author(s):  
Y. G. Kwak ◽  
S. K. Park ◽  
U. H. Kim ◽  
M. K. Han ◽  
J. S. Eun ◽  
...  

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.


1992 ◽  
Vol 220 (1) ◽  
pp. 35-41 ◽  
Author(s):  
Tatsuto Notsu ◽  
Kiyokazu Ohhashi ◽  
Isao Tanaka ◽  
Hiroshi Ishikawa ◽  
Takeshi Niho ◽  
...  

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