{"title":"持续注入血管紧张素II后大鼠血压变异性升高的机制分析。","authors":"Danfeng Jiang, Minami Matsuzaki, Yukiko Kawagoe, Kazuo Kitamura, Toshihiro Tsuruda, Koichi Kaikita, Yujiro Asada, Johji Kato","doi":"10.1155/2023/4201342","DOIUrl":null,"url":null,"abstract":"<p><strong>Objective: </strong>We reported that rats infused with angiotensin II (Ang II) are not only a model of hypertension but also of augmented 24 h blood pressure variability (BPV). In this study, we examined the mechanisms for Ang II-induced BPV, focusing on BP, heart rate (HR), baroreceptor reflex sensitivity (BRS), and medial area of the aortic arch.</p><p><strong>Methods: </strong>Nine-week-old male Wistar rats were infused with subcutaneous 5.2 <i>μ</i>g/kg/h Ang II with or without oral administration with 30 mg/kg/day azelnidipine for 14 days. BP and HR were recorded every 15 min under an unrestrained condition by a radiotelemetry system, while BPV was evaluated by standard deviation of BP. BRS was quantified by a sequence analysis, and medial thickness of the aortic arch was measured by microscopic examination.</p><p><strong>Results: </strong>BPV increased at days 7 and 14 following continuous infusion of Ang II. Before the infusion, a positive correlation was found between BP and HR, but it became negative at day 7 and then weakened or disappeared at day 14. BRS was slightly impaired at day 7 and significantly lowered at day 14, a phenomenon accompanied by thickened medial area of the aortic arch in Ang II-infused rats. Those Ang II-induced alterations were all significantly attenuated by azelnidipine.</p><p><strong>Conclusions: </strong>The present findings suggest sequential changes in the mechanisms behind augmented BPV in rats continuously infused with Ang II over 14 days.</p>","PeriodicalId":17330,"journal":{"name":"Journal of the Renin-Angiotensin-Aldosterone System","volume":"2023 ","pages":"4201342"},"PeriodicalIF":2.1000,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9833913/pdf/","citationCount":"0","resultStr":"{\"title\":\"Analysis of Mechanisms for Increased Blood Pressure Variability in Rats Continuously Infused with Angiotensin II.\",\"authors\":\"Danfeng Jiang, Minami Matsuzaki, Yukiko Kawagoe, Kazuo Kitamura, Toshihiro Tsuruda, Koichi Kaikita, Yujiro Asada, Johji Kato\",\"doi\":\"10.1155/2023/4201342\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<p><strong>Objective: </strong>We reported that rats infused with angiotensin II (Ang II) are not only a model of hypertension but also of augmented 24 h blood pressure variability (BPV). In this study, we examined the mechanisms for Ang II-induced BPV, focusing on BP, heart rate (HR), baroreceptor reflex sensitivity (BRS), and medial area of the aortic arch.</p><p><strong>Methods: </strong>Nine-week-old male Wistar rats were infused with subcutaneous 5.2 <i>μ</i>g/kg/h Ang II with or without oral administration with 30 mg/kg/day azelnidipine for 14 days. BP and HR were recorded every 15 min under an unrestrained condition by a radiotelemetry system, while BPV was evaluated by standard deviation of BP. BRS was quantified by a sequence analysis, and medial thickness of the aortic arch was measured by microscopic examination.</p><p><strong>Results: </strong>BPV increased at days 7 and 14 following continuous infusion of Ang II. Before the infusion, a positive correlation was found between BP and HR, but it became negative at day 7 and then weakened or disappeared at day 14. BRS was slightly impaired at day 7 and significantly lowered at day 14, a phenomenon accompanied by thickened medial area of the aortic arch in Ang II-infused rats. Those Ang II-induced alterations were all significantly attenuated by azelnidipine.</p><p><strong>Conclusions: </strong>The present findings suggest sequential changes in the mechanisms behind augmented BPV in rats continuously infused with Ang II over 14 days.</p>\",\"PeriodicalId\":17330,\"journal\":{\"name\":\"Journal of the Renin-Angiotensin-Aldosterone System\",\"volume\":\"2023 \",\"pages\":\"4201342\"},\"PeriodicalIF\":2.1000,\"publicationDate\":\"2023-01-01\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9833913/pdf/\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Journal of the Renin-Angiotensin-Aldosterone System\",\"FirstCategoryId\":\"3\",\"ListUrlMain\":\"https://doi.org/10.1155/2023/4201342\",\"RegionNum\":4,\"RegionCategory\":\"医学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q3\",\"JCRName\":\"PERIPHERAL VASCULAR DISEASE\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of the Renin-Angiotensin-Aldosterone System","FirstCategoryId":"3","ListUrlMain":"https://doi.org/10.1155/2023/4201342","RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q3","JCRName":"PERIPHERAL VASCULAR DISEASE","Score":null,"Total":0}
Analysis of Mechanisms for Increased Blood Pressure Variability in Rats Continuously Infused with Angiotensin II.
Objective: We reported that rats infused with angiotensin II (Ang II) are not only a model of hypertension but also of augmented 24 h blood pressure variability (BPV). In this study, we examined the mechanisms for Ang II-induced BPV, focusing on BP, heart rate (HR), baroreceptor reflex sensitivity (BRS), and medial area of the aortic arch.
Methods: Nine-week-old male Wistar rats were infused with subcutaneous 5.2 μg/kg/h Ang II with or without oral administration with 30 mg/kg/day azelnidipine for 14 days. BP and HR were recorded every 15 min under an unrestrained condition by a radiotelemetry system, while BPV was evaluated by standard deviation of BP. BRS was quantified by a sequence analysis, and medial thickness of the aortic arch was measured by microscopic examination.
Results: BPV increased at days 7 and 14 following continuous infusion of Ang II. Before the infusion, a positive correlation was found between BP and HR, but it became negative at day 7 and then weakened or disappeared at day 14. BRS was slightly impaired at day 7 and significantly lowered at day 14, a phenomenon accompanied by thickened medial area of the aortic arch in Ang II-infused rats. Those Ang II-induced alterations were all significantly attenuated by azelnidipine.
Conclusions: The present findings suggest sequential changes in the mechanisms behind augmented BPV in rats continuously infused with Ang II over 14 days.
期刊介绍:
JRAAS is a peer-reviewed, open access journal, serving as a resource for biomedical professionals, primarily with an active interest in the renin-angiotensin-aldosterone system in humans and other mammals. It publishes original research and reviews on the normal and abnormal function of this system and its pharmacology and therapeutics, mostly in a cardiovascular context but including research in all areas where this system is present, including the brain, lungs and gastro-intestinal tract.