著者

Shingo Tsujinaga Hiroyuki Iwano Yasuyuki Chiba Suguru Ishizaka Miwa Sarashina Michito Murayama Masahiro Nakabachi Hisao Nishino Shinobu Yokoyama Kazunori Okada Sanae Kaga Toshihisa Anzai

出版者

The Japanese Circulation Society

雑誌

Circulation Reports (ISSN:24340790)

巻号頁・発行日

vol.2, no.5, pp.271-279, 2020-05-08 (Released:2020-05-08)

参考文献数

27

被引用文献数

3

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Background:Ventilatory inefficiency during exercise assessed using the lowest minute ventilation/carbon dioxide production (V̇E/V̇CO2) ratio was recently proven to be a strong prognostic marker of heart failure (HF) regardless of left ventricular ejection fraction (LVEF). Its physiological background, however, has not been elucidated.Methods and Results:Fifty-seven HF patients underwent cardiopulmonary exercise testing and exercise-stress echocardiography. The lowest V̇E/V̇CO2ratio was assessed on respiratory gas analysis. Echocardiography was obtained at rest and at peak exercise. LVEF was measured using the method of disks. Cardiac output (CO) and the ratio of transmitral early filling velocity (E) to early diastolic tissue velocity (e’) were calculated using the Doppler method. HF patients were divided into preserved EF (HFpEF) and reduced EF (HFrEF) using the LVEF cut-off 40% at rest. Twenty-four patients were classified as HFpEF and 33 as HFrEF. In HFpEF, age (r=0.58), CO (r=−0.44), e’ (r=−0.48) and E/e’ (r=0.45) during exercise correlated with the lowest V̇E/V̇CO2ratio (P<0.05 for all). In contrast, in HFrEF, age (r=0.47) and CO (r=−0.54) during exercise, but not e’ and E/e’, correlated with the lowest V̇E/V̇CO2ratio.Conclusions:Loss of CO augmentation was associated with ventilatory inefficiency in HF regardless of LVEF, although lung congestion determined ventilatory efficiency only in HFpEF.

著者

Takafumi SHIMIZU Koji MIYAMOTO Kanako MIYAMOTO Eiichi MINAMI Yoko NISHIZAWA Moritoshi IINO Hideaki NOJIRI Hisakazu YAMANE Kazunori OKADA

出版者

(社)日本農芸化学会

雑誌

Bioscience, Biotechnology, and Biochemistry (ISSN:09168451)

巻号頁・発行日

vol.77, no.7, pp.1556-1564, 2013-07-23 (Released:2013-07-23)

参考文献数

41

被引用文献数

51

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Jasmonate plays key roles in plant growth and stress responses, as in defense against pathogen attack. Jasmonoyl-isoleucine (JA-Ile), a major active form of jasmonates, is thought to play a pivotal role in plant defense responses, but the involvement of JA-Ile in rice defense responses, including phytoalexin production, remains largely unknown. Here we found that OsJAR1 contributes mainly to stress-induced JA-Ile production by the use of an osjar1 Tos17 mutant. The osjar1 mutant was impaired in JA-induced expression of JA-responsive genes and phytoalexin production, and these defects were restored genetically. Endogenous JA-Ile was indispensable to the production of a flavonoid phytoalexin, sakuranetin, but not to that of diterpenoid phytoalexins in response to heavy metal stress and the rice blast fungus. The osjar1 mutant was also found to be more susceptible to the blast fungus than the parental wild type. These results suggest that JA-Ile production makes a contribution to rice defense responses with a great impact on stress-induced sakuranetin production.