Candesartan Cilexetil (TCV-116) is an angiotensin II receptor antagonist (IC50: 0.26 nM). After hydrolysis of candesartan cilexetil to candesartan during gastrointestinal absorption, candesartan selectively competes with angiotensin II for the binding of the angiotensin II receptor subtype 1 (AT1) in vascular smooth muscle, blocking angiotensin II-mediated vasoconstriction and inducing vasodilatation.

Five hours post-administration, Candesartan (1 mg/kg, orally) reduced blood pressure to a similar extent as Enalapril (10 mg/kg, orally) on both the 1st and 7th days. Candesartan significantly increased renal blood flow without altering the cardiac index. In rat myocardium with dilated cardiomyopathy (DCM), Candesartan dose-dependently improved functional markers and upregulated angiotensin (1-7), ACE2, and MAS1. Treatment with Candesartan in rats led to a reduction in various endoplasmic reticulum (ER) stress markers, apoptotic markers, and the number of apoptotic cells. Furthermore, Candesartan demonstrated a dose-dependent blockade of angiotensin-II in rats with dilated cardiomyopathy.

The prodrug of Candesartan is absorbed through the gastrointestinal tract and activated by ester hydrolysis into Candesartan. Candesartan then blocks the effects of angiotensin II on the angiotensin II type 1 receptors.

Kinetic Methods: In a typical kinetic run, 2.00 mL of assay buffer (20 mM HEPES, 0.5 mM EDTA, 0.035% SDS, pH 7.8) and Suc-Leu-Leu-Val-Tyr-AMC in DMSO are added to a 3 mL fluorescence cuvette, and the cuvette is placed in the jacketed cell holder of a fluorescence spectrophotometer. Reaction temperature is maintained at 37℃ by a circulating water bath. After the reaction solution has reached thermal equilibrium (5 minutes), 1 μL?10 μL of the stock enzyme solution is added to the cuvette. Reaction progress is monitored by the increase in fluorescence emission at 440 nm (λex= 380 nm) that accompanies cleavage of AMC from peptide-AMC substrates.