Capacitative Ca~(2+) entry mediate contraction in rat distal colon smooth muscle
- VernacularTitle:库容性Ca~(2+)内流介导大鼠远端结肠平滑肌收缩
- Author:
Daoping KE
;
Hua ZHOU
;
Zhongwen LI
;
Dehu KONG
;
Rong MA
- Publication Type:Journal Article
- Keywords:
capacitative Ca~(2+) entry;
distal colon smooth muscle;
rat;
thapsigargin
- From:
Chinese Pharmacological Bulletin
1987;0(03):-
- CountryChina
- Language:Chinese
-
Abstract:
Aim To investigate whether capacitative Ca~(2+) entry involved in excitation-contraction coupling in rat distal colon smooth muscle.Methods Changes of isolated organ's tension were monitored with force-displacement transducer and Powerlab 4/25T recording system.Results Thapsigargin(10 nmol?L~(-1)～1 ?mol?L~(-1))produced slowly developing sustained contractions in isolated distal colon smooth muscle strips of rats.The timed contractile responses to thapsigargin(10 n mol?L~(1)-1 ?mol?L~(-1)) were significantly different.The contractile response to Ca~(2+) reintroduction following incubation of strips in a Ca~(2+)-free Krebs in the presense of thapsigargin was significantly higher than in its absence(99%?28% vs 70%?8%).Contractile responses to Ca~(2+)reintroduction following depletion of sarcoplasmic reticulum Ca~(2+) stores with thapsigargin were attenuated by La~(3+),while unaffected by verapamil.Conclusion Contractile responses to Ca~(2+)reintroduction following depletion of sarcoplasmic reticulum Ca~(2+)stores with thapsigargin,are mediated by capacitative Ca~(2+)entry.The results suggested that CCE provided activator Ca~(2+)for the contraction and participated in excitation-contraction process in rat distal colon smooth muscle.
