PMID- 19097300
OWN - NLM
STAT- MEDLINE
DCOM- 20090326
LR  - 20141120
IS  - 2542-5641 (Electronic)
IS  - 0366-6999 (Linking)
VI  - 121
IP  - 22
DP  - 2008 Nov 20
TI  - Voltage-gated potassium channel Kv1.3 in rabbit ciliary epithelium regulates the 
      membrane potential via coupling intracellular calcium.
PG  - 2272-7
AB  - BACKGROUND: The cell layer of the ciliary epithelium is responsible for aqueous 
      humor secretion and maintenance. Ion channels play an important role in these 
      processes. The main aim of this study was to determine whether the 
      well-characterized members of the Kv1 family (Kv1.3) contribute to the Kv 
      currents in ciliary epithelium. METHODS: New Zealand White rabbits were 
      maintained in a 12 hours light/dark cycle. Ciliary epithelium samples were 
      isolated from the rabbits. We used Western blotting and immunocytochemistry to 
      identify the expression and location of a voltage-gated potassium channel Kv1.3 
      in ciliary body epithelium. Membrane potential change after adding of Kv1.3 
      inhibitor margatoxin (MgTX) was observed with a fluorescence method. RESULTS: 
      Western blotting and immunocytochemical studies showed that the Kv1.3 protein 
      expressed in pigment ciliary epithelium and nonpigment ciliary epithelium, 
      however it seemed to express more in the apical membrane of the nonpigmented 
      epithelial cells. One nmol/L margatoxin, a specific inhibitor of Kv1.3 channels 
      caused depolarization of the cultured nonpigmented epithelium (NPE) membrane 
      potential. The cytosolic calcium increased after NPE cell depolarization, this 
      increase of cytosolic calcium was partially blocked by 12.5 micromol/L dantrolene 
      and 10 micromol/L nifedipine. These observations suggest that Kv1.3 channels 
      modulate ciliary epithelium potential and effect calcium dependent mechanisms. 
      CONCLUSION: Kv1.3 channels contribute to K+ efflux at the membrane of rabbit 
      ciliary epithelium.
FAU - Li, Yan-feng
AU  - Li YF
AD  - State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen 
      University, Guangzhou, Guangdong 510060, China.
FAU - Zhuo, Ye-hong
AU  - Zhuo YH
FAU - Bi, Wei-na
AU  - Bi WN
FAU - Bai, Yu-jing
AU  - Bai YJ
FAU - Li, Yan-na
AU  - Li YN
FAU - Wang, Zhi-jian
AU  - Wang ZJ
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
PL  - China
TA  - Chin Med J (Engl)
JT  - Chinese medical journal
JID - 7513795
RN  - 0 (Kv1.3 Potassium Channel)
RN  - SY7Q814VUP (Calcium)
SB  - IM
MH  - Animals
MH  - Blotting, Western
MH  - Calcium/*metabolism
MH  - Ciliary Body/cytology/metabolism/physiology
MH  - Immunohistochemistry
MH  - In Vitro Techniques
MH  - Kv1.3 Potassium Channel/metabolism/*physiology
MH  - Membrane Potentials/physiology
MH  - Pigment Epithelium of Eye/cytology/metabolism/*physiology
MH  - Rabbits
EDAT- 2008/12/23 09:00
MHDA- 2009/03/27 09:00
CRDT- 2008/12/23 09:00
PHST- 2008/12/23 09:00 [entrez]
PHST- 2008/12/23 09:00 [pubmed]
PHST- 2009/03/27 09:00 [medline]
PST - ppublish
SO  - Chin Med J (Engl). 2008 Nov 20;121(22):2272-7.