[Effects of iptakalim on the proliferation of cultured rabbit pulmonary arterial smooth muscle cells induced by endothelin-1].
OBJECTIVE
To explore the effects of iptakalim on the proliferation of rabbit pulmonary arterial smooth muscle cell(PASMC) induced by endothelin-1(ET-1) in vitro.


METHODS
The experimental models of proliferation of rabbit PASMC induced by ET-1 in vitro were established and [(3)H]-thymidine ([(3)H]-TdR) incorporation and flow cytometric analysis(FCA) were used.


RESULTS
The value of [(3)H]-TdR incorporation in ET-1 group was increased 1.468 times higher than that in control group. Iptakalim at the concentrations of 10(-7) mol/L, 10(-6) mol/L, 10(-5) mol/L lowered [(3)H]-TdR incorporation by (19.8 +/- 4.6)%,(41.2 +/- 9.5)%, (54.7 +/- 10.1)%, declined the total of the DNA synthesis (S) and the mitotic phase (G(2)/M) ratios by (36.6 +/- 5.7)%, (42.6 +/- 4.9)%, (66.3 +/- 4.7)%, and increased the static phase (G(0)/G(1)) ratio by (14.4 +/- 3.0)%, (17.9 +/- 2.6)%, (27.9 +/- 3.2)%, respectively, compared with the value of the cells treated with ET-1 only (P < 0.01). Glibenclimide abolished the effect of iptakalim on [(3)H]-TdR incorporation.


CONCLUSIONS
Iptakalim has an inhibitory effect on PASMC proliferation induced by ET-1 through activating ATP sensitive potassium (K(ATP)) channels.
Xie
Wei-Ping
WP
Department of Respiratory Medicine, First Affiliated Hospital, Nanjing Medical University, Nanjing 210029, China.
Wang
Hong
H
Qi
Xu
X
Shen
Hong
H
Wang
Hai
H
Hu
Gang
G
D018528:ATP-Binding Cassette Transporters / Q000819:agonists; D000818:Animals; D002118:Calcium / Q000378:metabolism; D002453:Cell Cycle / Q000187:drug effects; D049109:Cell Proliferation / Q000187:drug effects*; D002478:Cells, Cultured; D004305:Dose-Response Relationship, Drug; D019332:Endothelin-1 / Q000494:pharmacology*; D005260:Female; D008297:Male; D009131:Muscle, Smooth, Vascular / Q000187:drug effects*; D024661:Potassium Channels, Inwardly Rectifying / Q000819:agonists; D011437:Propylamines / Q000494:pharmacology*; D011651:Pulmonary Artery / Q000166:cytology; D011817:Rabbits
D018528:ATP-Binding Cassette Transporters; D019332:Endothelin-1; C502260:N-(1-methylethyl)-1,1,2-trimethylpropylamine; D024661:Potassium Channels, Inwardly Rectifying; D011437:Propylamines; D002118:Calcium