Cellular Ca2+ dynamics in urinary bladder smooth muscle from transgenic mice overexpressing Na+-Ca2+ exchanger.
The rise of Ca(2+) concentration ([Ca(2+)](i)) by reducing external Na(+) in urinary bladder smooth muscle cells (UBSMCs) from transgenic mice overexpressing Na(+)/Ca(2+) exchanger type-1.3 (NCX1.3(tg/tg)) was about 4 times as large as that in the wild-type (WT). NCX1 protein expression in UB increased about 4-fold in NCX1.3(tg/tg). The Ca(2+) release by caffeine in UBSMCs was comparable between NCX1.3(tg/tg) and WT, but [Ca(2+)](i) decay was faster in NCX1.3(tg/tg). Contractions induced by acetylcholine, 60 mM K(+), or electrical stimulation were significantly smaller in UB segments of NCX1.3(tg/tg). NCX worked in Ca(2+)-extrusion mode during these contractions in UBSMCs of both WT and NCX1.3(tg/tg).
Murata
Hidemichi
H
Department of Molecular and Cellular Pharmacology, Graduate School of Pharmaceutical Sciences, Nagoya City University, Nagoya, Japan.
Hotta
Shingo
S
Sawada
Eiji
E
Yamamura
Hisao
H
Ohya
Susumu
S
Kita
Satomi
S
Iwamoto
Takahiro
T
Imaizumi
Yuji
Y
D000818:Animals; D002118:Calcium / Q000502:physiology*; D005786:Gene Expression Regulation; D008297:Male; D051379:Mice; D008822:Mice, Transgenic; D032389:Myocytes, Smooth Muscle / Q000378:metabolism*; D019831:Sodium-Calcium Exchanger / Q000096:biosynthesis* / Q000235:genetics; D001743:Urinary Bladder / Q000166:cytology / Q000378:metabolism*
D019831:Sodium-Calcium Exchanger; D002118:Calcium