Spectral analysis of renal microcirculation in spontaneously hypertensive rat (SHR) using the new developed wavelet method

使用新开发的小波方法对自发性高血压大鼠（SHR）肾微循环进行频谱分析

基本信息

批准号：
12671055
负责人：
KOMATSU Kazutoshi
金额：
$ 2.05万
依托单位：
Nihon University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
2000
资助国家：
日本
起止时间：
2000 至 2001
项目状态：
已结题

项目摘要

The kidney exhibits an ability to maintain the blood flow and glomerular filtration rate constant when the renal perfusion pressure is altered. Two factors contribute to this autoregulatory response, tubuloglomerular feedback and myogenic response.Previously, the renal autoregulation was studied using the micropuncture technique. In this study, we investigated the renal cortical blood flow using the spectral analysis (Maximum entropy method; MEM and Wavelet method) to determine the role of nitric oxide and angiotensin II on the renal autoregulation in SHR.Methods: Study 1. The chloralose-anesthetized male WKY/Izm, SHR/Izm and SHRSP/Izm (17 weeks old) were used. Renal homodynamic responses to NO synthesis inhibitor (L-NAME; 0.5, 1.0 mg/kg ia) were studied. Renal cortical blood flow (RBF) was measured by the laser-Doppler flowmeter. The spectral analysis of RBF variability was performed using maximum entropy method. TGF oscillations (30-50mHz) were confirmed by furosemide. Study 2. WKY/I … More zm and SHR/Izm were used. Angiotensin II (Ang II; 5, 15, 50, 100 ng/kg/min, 20-min iv) was infused. RBF was analyzed by Wavelet method.Results: (1) Left ventricle and aorta weights were increased in SHRSP. (2) Baseline mean arterial pressure (MAP) was 131±4, 182±3 and 214±3 mmHg in WKY, SHR and SHRSP, respectively. Baseline RBF was 49±1, 39±2, and 36±1 ml/min/100g in WKY, SHR and SHRSP, respectively. L-NAME increased MAP and decreased RBF. (3) L-NAME significantly increased TGF oscillations in WKY and SHR, but did not affect in SHRSP. (4) Wavelet could analyze RBF simultaneously ever 5 sec. Ang II tended to increased TGF oscillations in both strains. Compared with conventional spectrogram approach based on MEM, wavelet analysis yields a better time-frequency resolution.Conclusions: Tubuloglomerular feedback response was attenuated in SHRSP. Nitric oxide did not play a major role in TGF in SHRSP. This disorder of TGF might be affected by target organ damage. These results suggest that the effects of Nitric oxide on renal autoregulation are impaired in SHRSP. Wavelet method provides improved resolution of analysis and can be used as general indexes of TGF oscillations in rats. Less

肾脏表现出可维持血液过滤率的持续灌注压力，这有助于自动调节反应，肾小管肾脏反应，并恢复肌源性。）使用了一氧化氮和血管紧张素II对SHR的肾脏自动调节的作用。肾脏血流（RBF）通过激光多普勒流量计测量。使用最大熵方法（TGF振荡（30-50MHz））通过速尿进行了RBF的光谱分析。在SHRSP（2）基线平均动脉压（MAP）中增加了15、50、100 ng/kg/min，20分钟。 SHRSP，shrss和SHRSP中的1 ml/ min/ 100g，在SHRSP中不影响shrsp。 MEM LES释放的分辨率。用作大鼠TGF振荡的一般指数