Alteration of the increase in intracellular [Ca(2+)] in proliferating smooth muscle cells.
Proliferation of smooth muscle cells (SMC) has a role in the development of cardiovascular diseases. We investigated the alteration of contractile signals in proliferating SMC by measuring the increase in intracellular [Ca(2+)] to endothelin-1 (ET-1), noradrenaline (NA), or angiotensin II (AgII). We found that the increase in intracellular [Ca(2+)] by NA or ET-1 decreased in proliferating SMC in comparison to growth-arrested SMC. The increase in intracellular [Ca(2+)] by AgII was stable between the cells. Immunoblotting of inositol 1,4,5-trisphosphate receptors (IP(3)Rs) which are responsible for the mobilization of Ca(2+) by those vasoactive substances revealed that expression of IP(3)R type 1 and type 2 was decreased. Expression of IP(3)R type 3 was increased. The altered Ca(2+) signaling by the cell growth might involve the expression of IP(3)R subtypes.
Sugiyama
T
T
Vessel Research Laboratory Co., Ltd., 3-6-6 Asahimachi, Machida-shi, Tokyo, 194, Japan. sugiyama@hri.co.jp
Hasegawa
K
K
Yanai
N
N
Mikoshiba
K
K
Obinata
M
M
Matsuda
Y
Y
D000818:Animals; D002118:Calcium / Q000378:metabolism*; D002455:Cell Division; D002478:Cells, Cultured; D004261:DNA Replication; D009131:Muscle, Smooth, Vascular / Q000166:cytology* / Q000378:metabolism*
D002118:Calcium