Title Influence of interleukin-2 on Ca2+ handling in rat ventricular myocytes
نویسندگان
چکیده
In the present study we examined the effect of interleukin-2 (IL-2) on cardiomyocyte calcium handling. The effects of steady-state and transient changes in stimulation frequency on the intracellular Ca transient were investigated in isolated ventricular myocytes by spectrofluorometry. In the steady state (0.2 Hz) IL-2 (200 U/ml) decreased the amplitude and prolonged the decay of the electrically stimulated and caffeine-induced Ca transients. At 1.25 mM [Ca]o, when the stimulation frequency increased from 0.2 to 1.0 Hz, diastolic Ca level and peak [Ca]i as well as the amplitude of the transient increased. The positive frequency relationships of the peak and amplitude (peak minus diastolic) [Ca]i were blunted in the IL-2-treated myocytes and this was not normalized by increasing [Ca]o to 2.5 mM. IL-2 inhibited the frequency relationship of caffeine-induced Ca release. Blockade of sarcoplasmic reticulum (SR) Ca-ATPase with thapsigargin resulted in a significant reduction of the amplitude/frequency relationship of the transient similar to that induced by IL-2. The restitutions were not different between control and IL-2 groups at 1.25 mM [Ca]o, which was slowed in
منابع مشابه
Influence of interleukin-2 on Ca2+ handling in rat ventricular myocytes.
In the present study, we examined the effect of interleukin-2 (IL-2) on cardiomyocyte Ca(2+) handling. The effects of steady-state and transient changes in stimulation frequency on the intracellular Ca(2+) transient were investigated in isolated ventricular myocytes by spectrofluorometry. In the steady state (0.2 Hz) IL-2 (200 U/ml) decreased the amplitude of Ca(2+) transients induced by electr...
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