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Diverse regulation of Cl − channel on ANP release in beating rat atria
Author(s) -
Han Jeong Hee,
Bai Guang Yi,
Yuan Kuichang,
Kim Sung Zoo,
Kim Suhn Hee
Publication year - 2006
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.20.5.a824-d
Subject(s) - niflumic acid , dids , atrium (architecture) , chemistry , medicine , channel blocker , contractility , secretion , endocrinology , biochemistry , calcium , atrial fibrillation , membrane
The aim of this study was to examine the diverse role of Cl ‐ selective anion channels in the ANP release using isolated perfused beating rat atria. Atrial wall stretch was superimposed for 40 min after 70 min drug infusions by elevating the height of outflow catheter connected to the perfused beating atrium. At basal condition, the ANP secretion and ECF translocation from right atrium were higher than left atrium. The responsiveness of atrial contractility and ECF translocation to stretch were lower in right atrium but the responsiveness of ANP secretion to stretch was similar, as compared to left atrium. Therefore, the ANP secretion in terms of ECF translocation (i. e. interstitial ANP concentration) in right atrium was higher than in left atrium. As to define the effect of Cl − channel on ANP secretion, Ca 2+ activated Cl ` channel blocker(niflumic acid) or swelling activated Cl − channel blocker(4, 4′‐ diisothiocyanatostilbene‐2,2′‐disulfonic acid, DIDS) was used. DIDS(100uM) did not show any significant changes in atrial contractility, ECF translocation and ANP secretion by stretch. Interestingly, niflumic acid caused augmentation of stretch‐induced ANP secretion without changing contractility and ECF translocation. However, this effect of niflumic acid in left atrium was not observed in right atrium. These results show that Ca 2+ activated Cl − channel may be involved in the regulation of stretch‐induced ANP secretion and the exact mechanisms for the different atrial responses to niflumic acid are under the study. Supported by KOSEF(R01‐2003‐000‐10507‐0) and by the Regional Research Centers Program of the Korean Ministry of Education & Human Resources Development through the Center for Health Care Technology Development.