›› 2019, Vol. 39 ›› Issue (9): 984-.doi: 10.3969/j.issn.1674-8115.2019.09.008

• Original article (Basic research) • Previous Articles     Next Articles

Effect of extracellular potassium on the activity of distal renal tubule in mice

YANG Yang, ZHANG Ya, GUO Qin, ZHANG Chong   

  1. Department of Nephrology and Rheumatology, Xinhua Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200092, China
  • Online:2019-09-28 Published:2019-11-02
  • Supported by:
    General Program of National Natural Science Foundation of China, 81570634, 81770706; Shanghai Municipal Education Commission—Gaofeng Clinical Medicine Support, 20161418)。

Abstract: Objective · To investigate the effect of extracellular potassium (K+) concentration on the activities of sodium chloride co-transporter (NCC) and large conductance Ca2+-activated K+ channel (BK) in distal renal tubule of mice. Methods · Six specific pathogen free (SPF) C57BL/6 mice aged 8 to 10 weeks were sacrificed, and the kidney slices were made with previously reported method. Then, these slices were incubated randomly in normal K+, high K+, BaCl2 and RbCl solutions, respectively. The abundance and phosphorylation level of NCC in kidney slices at different K+ concentrations and different time courses were detectedWestern blotting. The overall and membrane s of BK in kidney slices were also detected after incubation with different K+ solutions for 2 h. Results · Compared with normal K+ solution, NCC phosphorylation level was significantly decreased after incubation with high K+ solution for 5, 15, 30 min (all P<0.05), and NCC phosphorylation level was also decreased after intervention with K+ channel inhibitor Ba2+ or Rb+ (both P<0.05). After the treatment with high K+ solution for 2 h, neither the overall cell of BKα subunit and β4 subunit, nor membrane of BKα subunit was found significant changes compared with normal K+ incubation. Conclusion · High K+ can directly down-regulate NCC phosphorylation level, which may be preparation for kaliuresis of the downstream tubule of distal convoluted tubule.

Key words: distal transporter, sodium chloride co-transporter (NCC), large conductance Ca2+-activated K+ channel (BK), potassium ion (K+)

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