KCNQ1/KCNE1 K+ channel and P2Y4 receptor are co-expressed from the time of birth in the apical membrane of rat strial marginal cells.
CONCLUSIONS
KCNQ1/KCNE1 K(+) channels and P2Y(4) receptors are expressed in the apical membrane of rat strial marginal cells from postnatal day 1 (P1) and maintained throughout development.


OBJECTIVE
The purpose of the present study was to investigate the developmental expression of KCNQ1/KCNE1 K(+) channel and of P2Y(4), which is an important metabotropic regulator of KCNQ1/KCNE1 K(+) channel in strial marginal cells.


METHODS
Sprague-Dawley rats at different stages of development (P1, P3, P5, P7, P14, and P21) were studied. The spiral ligament with the stria vascularis was detached from the cartilaginous or bony cochlea and prepared for a voltage-sensitive vibrating probe and immunohistochemistry.


RESULTS
Chromanol 293B, a blocker of KCNQ1/KCNE1 K(+) channel, inhibited short-circuit currents (I ( sc )) from P1 to P21. Similarly, I ( sc ) were found to be decreased by uridine 5'-triphosphate at all ages. The antagonist profiles indicated that the apical P2Y receptor is P2Y(4) subtype. KCNQ1, KCNE1, and P2Y(4) were immunolocalized in the apical region of stria vascularis at P1.
Hur
Dong Gu
DG
Department of Otorhinolaryngology-Head and Neck Surgery, Gyeongsang National University Hospital, Jinju, Korea.
Lee
Jun Ho
JH
Oh
Seung-Ha
SH
Kim
Young Ho
YH
Lee
Jin Hee
JH
Shin
Dong Hoon
DH
Chang
Sun O
SO
Kim
Chong-Sun
CS
D000818:Animals; D000831:Animals, Newborn; D002462:Cell Membrane / Q000378:metabolism*; D002478:Cells, Cultured; D002839:Chromans / Q000494:pharmacology; D004566:Electrodes; D007150:Immunohistochemistry; D051657:KCNQ1 Potassium Channel / Q000378:metabolism*; D026902:Potassium Channel Blockers / Q000494:pharmacology; D024642:Potassium Channels, Voltage-Gated / Q000378:metabolism*; D051381:Rats; D017207:Rats, Sprague-Dawley; D018048:Receptors, Purinergic P2 / Q000378:metabolism*; D013316:Stria Vascularis / Q000166:cytology*; D013449:Sulfonamides / Q000494:pharmacology; D014732:Vibration
D002839:Chromans; D051657:KCNQ1 Potassium Channel; C092068:Kcne1 protein, mouse; C496910:Kcnq1 protein, mouse; D026902:Potassium Channel Blockers; D024642:Potassium Channels, Voltage-Gated; D018048:Receptors, Purinergic P2; D013449:Sulfonamides; C104749:purinoceptor P2Y4; C103474:6-cyano-4-(N-ethylsulfonyl-N-methylamino)-3-hydroxy-2,2-dimethylchromane