Caldaret is an intracellular Ca2+ handling modulator that acts through reverse mode Na+/Ca2+ exchanger inhibition.
Caldaret (MCC-135) is demonstrated to restore Ca2+-ATPase activity of the sarcoplasmic reticulum (SR) isolated from the myocardium acutely exposed to ischemia and reperfusion in vitro[2].
Caldaret, an intracellular Ca2+ handling modulator, limits infarct size of reperfused canine heart. The cardioprotective effect of Caldaret, a novel intracellular Ca2+ handling modulator that acts through reverse-mode Na+/Ca2+ exchanger inhibition and potential sarcoplasmic reticulum (SR) Ca2+ uptake enhancement, against reperfusion injury is investigated. Intravenously infused Caldaret (3 or 30 microg/kg per hour) for 30 min at left circumflex (LCX)-reperfusion markedly reduces infarct size (by 51.3% or 71.9%, respectively). The amelioration of intracellular Ca2+ handling dysfunction achieved by Caldaret leads to cardioprotective effects against reperfusion injury following prolonged ischemia[1]. Caldaret (MCC-135) is a new potent compound with beneficial effects in heart failure. In diabetic rats, Caldaret decreases TR80 significantly without significant effect on developed tension (DT). Caldaret has minimal effects on SR Ca2+ uptake in normal rats, that is observed as increased SR Ca2+ uptake at uptake time of 20 and 30 s at the highest concentration of 10 μM. In diabetic rats, Caldaret increases SR Ca2+ uptake all over the range of uptake time. Both initial rate of SR Ca2+ uptake and the amount of Ca2+ accumulated in the SR with longer uptake time are increased by Caldaret[2].
[1]. Kawasumi H, et al. Caldaret, an intracellular Ca2+ handling modulator, limits infarct size of reperfused canine heart. J Pharmacol Sci. 2007 Feb;103(2):222-33. [2]. Satoh N, et al. Lusitropic effect of MCC-135 is associated with improvement of sarcoplasmic reticulum function in ventricular muscles of rats with diabetic cardiomyopathy. J Pharmacol Exp Ther. 2001 Sep;298(3):1161-6.