Simultaneous treatment with azelnidipine and olmesartan inhibits apoptosis of Hl-1 cardiac myocytes expressing E334k cMyBPC.

BACKGROUND: Apoptosis appears to play an important role in the pathogenesis of hypertrophic cardiomyopathy (HCM). We have previously reported 3 HCM patients carrying the E334K MYBPC3, and that heterologous expression of E334K cMyBPC in cultured cells induced apoptosis. The purpose of this study was to identify pharmacological agents that would inhibit apoptosis in HL-1 cardiomyocytes expressing E334K cMyBPC. METHODS AND RESULTS: E334K cMyBPC expression in cells increased levels of pro-apoptosis (p53, Bax and cytochrome c) and decreased levels of anti-apoptosis (Bcl-2 and Bcl-XL). While the beta blocker carvedilol (1 µM) normalized the level of p53 and Bcl-2 and the calcium channel blocker (CCB) bepridil (0.5 µM) normalized that of Bcl-2, both the CCB azelnidipine (1 µM) and the angiotensin receptor blocker (ARB) olmesartan (10 µM) normalized those of p53, Bax, cytochrome c, and Bcl-XL. Among those proteins, cytochrome c was the one which showed the highest degree of change. Both azelnidipine (0.1 µM) and olmesartan (1 µM) reduced the level of cytochrome c by 40.2 ± 4.3% and 31.3 ± 5.1%, respectively. The CCB amlodipine and the ARB valsartan reduced it only by 19.1 ± 2.1% and 20.1 ± 5.2%, respectively. Flow cytometric analysis and annexin V staining showed that treatment of cells with azelnidipine (0.1 µM) plus olmesartan (0.3 µM) or that with amlodipine (0.1 µM) plus valsartan (0.3 µM) reduced the number of apoptotic cells by 35.8 ± 10.5% and 18.4 ± 3.2%, respectively. CONCLUSION: Azelnidipine plus olmesartan or amlodipine plus valsartan inhibited apoptosis of HL-1 cells expressing E334K cMyBPC, and the former combination was more effective than the latter.

A vasodilating ß1 blocker celiprolol inhibits muscular release of uric acid precursor in patients with essential hypertension.

Although nonvasodilating ß1 blockers increase the levels of uric acid in serum, it is not known whether vasodilating ß1 blockers have a similar effect. In the present study, we evaluated the effect of celiprolol on the release of hypoxanthine, a uric acid precursor, from muscles after an exercise. We used the semi-ischemic forearm test to examine the release of lactate (ΔLAC), ammonia (ΔAmm), and hypoxanthine (ΔHX) before and 4, 10, and 60 min after an exercise in 18 hypertensive patients as well as 4 normotensive subjects. Before celiprolol treatment, all the levels of ΔHX and ΔAmm, and ΔLAC were increased by semi-ischemic exercise in hypertensive patients, and the increases were remarkably larger than those in normotensive subjects. Celiprolol decreased both systolic and diastolic pressure. It also decreased the levels of ΔHX and ΔAmm without changes in ΔLAC after an exercise. These findings also were confirmed by summation of each metabolite (ΣΔMetabolites). Celiprolol caused a marginal decrease of serum uric acid, but the difference was not statistically significant. On the other hand, nonvasodilating ß1 blockers did not suppress the levels of ΔHX and ΔAmm, whereas they significantly increased ΔLAC after an exercise. Celiprolol improved energy metabolism in skeletal muscles. It suppressed HX production and consequently did not adversely affect serum uric acid levels.