Modulation of interleukin-2 on the positive effect of isoproterenol in the isolated cardiomyocytes
- VernacularTitle:白细胞介素-2对心肌?-肾上腺素受体作用的调制
- Author:
Linlin WANG
;
Qiang XIA
;
Yingying CHEN
;
Chunmei CAO
;
Xiong ZHANG
- Publication Type:Journal Article
- Keywords:
Myocardium;
Cells;
Interleukin-2;
Isoproterenol
- From:
Chinese Journal of Pathophysiology
1986;0(01):-
- CountryChina
- Language:Chinese
-
Abstract:
AIM: To explore the effects and mechanism of interleukin-2 (IL-2) on the positive effect of isoproterenol (ISO) in the isolated rat cardiomyocytes. METHODS: Enzymatically isolated cardiomyocytes were used. Peak twitch amplitude and maximal velocity of shortening/relaxation (?dL/dt_~max ) in the isolated cardiomyocytes were recorded with a microscope coupled to a charge-coupled device camera and [Ca~2+ ]i transients were determined with a fluorometric ratio method by using Fura-2/AM as Ca~2+ indicators. RESULTS: ① ISO increased the peak twitch amplitude and ?dL/dt_~max of the isolated cardiomyocytes. Perfusion for 15 min with IL-2 at 2?103 U/L, which had no effect at all, attenuated the enhancing effect of ISO on the peak twitch amplitude and ?dL/dt_~max . ② ISO increased the [Ca~2+ ]i transients of the single ventricular myocytes in a dose dependent manner and the corresponding EC_~50 values of ISO was (0.12?0.01) ?mol/L. Perfusion for 15 min with IL-2 at 2?103 U/L, which had no effect on the ~[Ca~2+ ]i transient at all, attenuated the enhancing effect of ISO and the corresponding EC_~50 was (0.44?0.06) ?mol/L. ③ The electrically induced [Ca~2+ ]i transient was significantly increased by pretreatment with 20 mg/L cholera toxin for ~12 h. The elevation of the [Ca~2+ ]i transient induced by cholera toxin was significantly attenuated by 2?103 U/L IL-2. ④ Forskolin (1 ?mol/L), the activator of adenyl cyclase, significantly increased the electrically induced [Ca~2+ ]i transient, which was attenuated by IL-2 at 2?103 U/L. CONCLUSION: IL-2 inhibits the positive effect of isoproterenol in the isolated single ventricular myocytes, in which Gs protein and adenyl cyclase are involved. [
