- 著者
- Takahiro Tokuhisa Masafumi Yano Masakazu Obayashi Toshiyuki Noma Mamoru Mochizuki Tetsuro Oda Shinichi Okuda Masahiro Doi Jinyao Liu Yasuhiro Ikeda Takeshi Yamamoto Tomoko Ohkusa Masunori Matsuzaki
- 出版者
- The Japanese Circulation Society
- 雑誌
- Circulation Journal (ISSN:13469843)
- 巻号頁・発行日
- vol.70, no.6, pp.777-786, 2006 (Released:2006-05-25)
- 参考文献数
- 42
- 被引用文献数
- 18 20
Background The Ca2+ regulatory proteins in the sarcoplasmic reticulum (SR) play a key role in the pathogenesis of heart failure. In the present study the effect of chronic β-receptor-stimulation on cardiac and SR functions was assessed, with or without angiotensin-II receptor antagonist treatment recently reported to have anti-β-adrenergic activity. Methods and Results Rats were treated with isoproterenol with (+) or without (-) candesartan (CAN) and then SR vesicles were isolated from the left ventricular muscle. Both Ca2+-uptake and the amount of SR Ca2+-ATPase were significantly lower in the CAN (-) group than in the shams, but those were almost normally restored in the CAN (+). Although the level of the protein kinase A (PKA)-phosphorylation of the SR Ca2+ release channel, known as the ryanodine receptor (RyR2), was elevated in the CAN (-), no Ca2+-leak was detected. However, SIN-1 (O2 - donor) induced Ca2+-leak in the CAN (-) at a 10-fold lower dose than in the sham and CAN (+). In cardiomyocytes, SIN-1 decreased cell shortening and the peak Ca2+ transient and prolonged time from peak to 70% decline in CAN (-), again at 10-fold lower dose than in the sham and CAN (+). Conclusion Chronic β-receptor-stimulation did not induce any Ca2+-leak from the SR, whereas Ca2+-leak was easily induced when oxidative stress was applied to the PKA-phosphorylated RyR2. Candesartan not only improved Ca2+-uptake, but also prevented PKA-phosphorylation, rendering the SR less susceptible to Ca2+-leak. (Circ J 2006; 70: 777 - 786)
- 著者
- Hiroshi Kurazumi Ryo Suzuki Bungo Shirasawa Yosuke Miyazaki Hiroki Tateishi Tetsuro Oda Takayuki Okamura Akihito Mikamo Masafumi Yano Kimikazu Hamano
- 出版者
- The Japanese Circulation Society
- 雑誌
- Circulation Journal (ISSN:13469843)
- 巻号頁・発行日
- pp.CJ-21-0949, (Released:2022-02-09)
- 参考文献数
- 23
- 被引用文献数
- 2
Background:Transcatheter aortic valve implantation (TAVI) is increasingly being performed in very elderly patients, although its efficacy and validity remain unclear. This study evaluated real-world TAVI outcomes in Japanese nonagenarians with severe aortic stenosis.Methods and Results:This single-center study retrospectively assessed the early and long-term clinical outcomes of TAVI in nonagenarians (n=35) and in patients aged <90 years (group Y; n=171). There were no in-hospital deaths in either group. The device success rate and early safety were comparable between the 2 groups. The 5-year rates of freedom from cardiac events and deaths were equivalent in both groups. The cumulative survival rate at 5 years was non-significantly lower in nonagenarians (32.6% in nonagenarians vs. 57.5% in patients aged <90 years, P=0.49). There were no differences in the 5-year survival between nonagenarians after TAVI and the sex- and age-matched populations (P=0.18). The Cox regression model revealed that lower hemoglobin levels were associated with all-cause mortality (P=0.02), and age ≥90 years was not associated with all-cause mortality.Conclusions:The early and long-term clinical outcomes of TAVI for selected Japanese nonagenarians were comparable to those in patients aged <90 years. Nonagenarians who underwent TAVI achieved an acceptable prognosis compared to the sex- and age-matched population; thus, TAVI appears to be effective for treating aortic stenosis in Japanese nonagenarians.