Differential Functional Expression of Clotrimazole-sensitive Ca2+-activated K+ Current in Bal-17 and WEHI-231 Murine B Lymphocytes.
- Author:
Haifeng ZHENG
1
;
Jae Hong KO
;
Joo Hyun NAM
;
Yung E EARM
;
Sung Joon KIM
Author Information
1. Department of Physiology and Biophysics, Seoul National University College of Medicine, Seoul 110-799, Korea. sjoonkim@snu.ac.kr
- Publication Type:Original Article
- Keywords:
B lymphocyte;
Potassium channel;
Ca2+-activated K+ channel;
Clotrimazol;
WEHI-231;
Bal-17
- MeSH:
B-Lymphocytes*;
Cell Line;
Clotrimazole;
Lymphocytes;
Membranes;
Potassium Channels;
Potassium Channels, Calcium-Activated;
RNA, Messenger
- From:The Korean Journal of Physiology and Pharmacology
2006;10(1):19-24
- CountryRepublic of Korea
- Language:English
-
Abstract:
The intermediate conductance Ca2+-activated K+ channels (SK4, IKCa1) are present in lymphocytes, and their membrane expression is upregulated by various immunological stimuli. In this study, the activity of SK4 was compared between Bal-17 and WEHI-231 cell lines which represent mature and immature stages of murine B lymphocytes, respectively. The whole-cell patch clamp with high-Ca2+ (0.8microM) KCl pipette solution revealed a voltage-independent K+ current that was blocked by clotrimazole (1 mM), an SK4 blocker. The expression of mRNAs for SK4 was confirmed in both Bal-17 and WEHI-231 cells. The density of clotrimazole-sensitive SK4 current was significantly larger in Bal-17 than WEHI-231 cells (-11.4+/-3.1 Vs. -5.7+/-1.15 pA/pF). Also, the chronic stimulation of B cell receptors (BCR) by BCR-ligation (anti-IgM Ab, 3microgram/ml, 8~12 h) significantly upregulated the amplitude of clotrimazole-sensitive current from -11.4+/-3.1 to -53.1+/-8.6 pA/pF in Bal-17 cells. In WEHI-231 cells, the effect of BCR-ligation was significantly small (-5.7+/-1.15 to -9.0+/-1.00 pA/pF). The differential expression and regulation by BCR-ligation might reflect functional changes in the maturation of B lymphocytes.
