AIM: To evaluate the role of chymase in blood pressure regulation and its actions on tissue renin-angiotensin system.METHODS: A two-kidney, one-clip(2K1C) hypertension model was developed in Syrian hamsters, which hav...AIM: To evaluate the role of chymase in blood pressure regulation and its actions on tissue renin-angiotensin system.METHODS: A two-kidney, one-clip(2K1C) hypertension model was developed in Syrian hamsters, which have a human-type chymase. Either an angiotensin(Ang) converting enzyme(ACE) inhibitor(ACE-I; temocapril, 30 mg/kg per day), Ang Ⅱ type 1 receptor antagonist(ARB; CS866, 10 mg/kg per day), or vehicle was administered, beginning 2 wk after renal artery clipping and continued for 16 wk. At the end of this protocol, hearts, aortas, and lungs were removed, and total Ang Ⅱ-forming activities and ACE- and chymasedependent Ang Ⅱ-forming activities were determined.RESULTS: After renal artery clipping, systolic blood pressure in the vehicle group was significantly higher compared with that in a sham-operated group throughoutthe experimental period. Both ACE-I and ARB treatments revealed similar antihypertensive effects. Moreover, in the vehicle group, cardiac total and chymase-dependent Ang Ⅱ-forming activities significantly increased at 18 wk after clipping. Further, cardiac total and chymase-dependent Ang Ⅱ-forming activities decreased significantly after ACE-I or ARB treatment for 16 wk. In addition, chymase-dependent Ang Ⅱ-forming activity significantly increased in the aorta, although these changes were inhibited only by ARB. ARB treatment was more effective compared with ACE-I treatment in reversing the changes in tissue Ang Ⅱ formation, particularly in the aorta, despite their similar antihypertensive effects.CONCLUSION: Chymase does not play a major role in maintaining blood pressure and tissue ACE and chymase are regulated in a tissue-dependent manner in 2K1 C hamster.展开更多
Apolipoprotein A-Ⅱ(APOA-Ⅱ) is the second most abundant apolipoprotein of high-density lipoprotein(HDL)synthesized mainly by the liver and to a much lesser extent by the intestine. Transgenic mice overexpressing huma...Apolipoprotein A-Ⅱ(APOA-Ⅱ) is the second most abundant apolipoprotein of high-density lipoprotein(HDL)synthesized mainly by the liver and to a much lesser extent by the intestine. Transgenic mice overexpressing human APOA-Ⅱ present abnormal lipoprotein composition and are prone to atherosclerosis, though in humans the role for APOA-Ⅱ in coronary heart disease remains controversial. Here, we investigated the effects of overexpressed APOA-Ⅱ on HDL structure and function, adipose tissue metabolic activity, glucose tolerance and insulin sensitivity. C57BL/6 mice were infected with an adenovirus expressing human APOA-Ⅱ or a control adenovirus Ad GFP, and five days post-infection blood and tissue samples were isolated. APOA-Ⅱ expression resulted in distinct changes in HDL apoproteome that correlated with increased antioxidant and anti-inflammatory activities. No effects on cholesterol efflux from RAW 264.7 macrophages were observed. Molecular analyses in white adipose tissue(WAT) indicated a stimulation of oxidative phosphorylation coupled with respiration for ATP production in mice overexpressing APOA-Ⅱ. Finally, overexpressed APOA-Ⅱ improved glucose tolerance of mice but had no effect on the response to exogenously administered insulin. In summary, expression of APOA-Ⅱ in C57BL/6 mice results in pleiotropic effects with respect to HDL functionality, adipose tissue metabolism and glucose utilization, many of which are beneficial to health.展开更多
文摘AIM: To evaluate the role of chymase in blood pressure regulation and its actions on tissue renin-angiotensin system.METHODS: A two-kidney, one-clip(2K1C) hypertension model was developed in Syrian hamsters, which have a human-type chymase. Either an angiotensin(Ang) converting enzyme(ACE) inhibitor(ACE-I; temocapril, 30 mg/kg per day), Ang Ⅱ type 1 receptor antagonist(ARB; CS866, 10 mg/kg per day), or vehicle was administered, beginning 2 wk after renal artery clipping and continued for 16 wk. At the end of this protocol, hearts, aortas, and lungs were removed, and total Ang Ⅱ-forming activities and ACE- and chymasedependent Ang Ⅱ-forming activities were determined.RESULTS: After renal artery clipping, systolic blood pressure in the vehicle group was significantly higher compared with that in a sham-operated group throughoutthe experimental period. Both ACE-I and ARB treatments revealed similar antihypertensive effects. Moreover, in the vehicle group, cardiac total and chymase-dependent Ang Ⅱ-forming activities significantly increased at 18 wk after clipping. Further, cardiac total and chymase-dependent Ang Ⅱ-forming activities decreased significantly after ACE-I or ARB treatment for 16 wk. In addition, chymase-dependent Ang Ⅱ-forming activity significantly increased in the aorta, although these changes were inhibited only by ARB. ARB treatment was more effective compared with ACE-I treatment in reversing the changes in tissue Ang Ⅱ formation, particularly in the aorta, despite their similar antihypertensive effects.CONCLUSION: Chymase does not play a major role in maintaining blood pressure and tissue ACE and chymase are regulated in a tissue-dependent manner in 2K1 C hamster.
基金supported financially by the program"Support of Young Investigators"MIS No.5005458 that was co-financed by the Operational Program"Human Resources Development,Education and Lifelong Learning"and by the European Union(European Social Fund)and Greek national funds。
文摘Apolipoprotein A-Ⅱ(APOA-Ⅱ) is the second most abundant apolipoprotein of high-density lipoprotein(HDL)synthesized mainly by the liver and to a much lesser extent by the intestine. Transgenic mice overexpressing human APOA-Ⅱ present abnormal lipoprotein composition and are prone to atherosclerosis, though in humans the role for APOA-Ⅱ in coronary heart disease remains controversial. Here, we investigated the effects of overexpressed APOA-Ⅱ on HDL structure and function, adipose tissue metabolic activity, glucose tolerance and insulin sensitivity. C57BL/6 mice were infected with an adenovirus expressing human APOA-Ⅱ or a control adenovirus Ad GFP, and five days post-infection blood and tissue samples were isolated. APOA-Ⅱ expression resulted in distinct changes in HDL apoproteome that correlated with increased antioxidant and anti-inflammatory activities. No effects on cholesterol efflux from RAW 264.7 macrophages were observed. Molecular analyses in white adipose tissue(WAT) indicated a stimulation of oxidative phosphorylation coupled with respiration for ATP production in mice overexpressing APOA-Ⅱ. Finally, overexpressed APOA-Ⅱ improved glucose tolerance of mice but had no effect on the response to exogenously administered insulin. In summary, expression of APOA-Ⅱ in C57BL/6 mice results in pleiotropic effects with respect to HDL functionality, adipose tissue metabolism and glucose utilization, many of which are beneficial to health.
