Roles of Renal Dopamine and Kallikrein-Kinin Systems in Antihypertensive Mechanisms of Exercise in Rats.
スポンサーリンク
概要
- 論文の詳細を見る
We have previously shown that both renal dopamine (DA) and kallikrein-kinin systems are activated by exercise in mild hypertensives. We aimed to confirm the effects of exercise on the renal DA system and the stimulatory effects of DA on the renal kallikrein-kinin system in rats. In experiment 1, 12 male Dahl salt-sensitive (DS) rats given a 4% salt diet were divided into two groups. Rats in the exercise group were forced to run at 8m/min, 60min/day, 5 days /week for 4 weeks. Daily urinary volume, urinary excretion of sodium, free DA, and kallikrein activity were measured weekly. Renal aromatic-L-amino-acid decarboxylase (AADC) activities were assayed at the end of the experiment. In experiment 2, 15 male Sprague-Dawley (SD) rats were randomly divided into 3 groups, a DA-5 (5μg of DA/kg/min), a DA-10 (10μg of DA/kg/min), and a control group. DA or vehicle was administered subcutaneously with an osmotic pump for 2 weeks. Daily urinary volume, urinary excretion of sodium, aldosterone, DA, and kallikrein activity were measured weekly. Plasma renin activity, aldosterone concentration, and renal kallikrein mRNA levels were determined at the end of the experiment. In experiment 1, urinary excretion of free DA and renal AADC activities in the exercise group were significantly higher than those in the non-exercise group at week 4. In experiment 2, renal kallikrein mRNA levels and urinary volume were significantly increased in the DA-10 group compared to the control group, although there were no differences in urinary kallikrein activities. Plasma aldosterone concentration was significantly decreased in the DA-10 group compared to that in the control group despite a lack of differences in plasma renin activities. In conclusion, exercise increased the urinary excretion of free DA, probably through increased renal AADC activity in DS rats. DA amplified renal kallikrein mRNA levels and decreased plasma aldosterone levels, probably through its suppression of aldosterone in the adrenal glands. Activation of the kallikrein-kinin system might be counteracted by post-transcriptional modification of aldosterone. These results suggest that exercise enhances renal dopamine production by activating renal AADC activity, which in turn stimulates the renal kallikrein-kinin system. (Hypertens Res 2000; 23: 511-519)
- 日本高血圧学会の論文
日本高血圧学会 | 論文
- Telmisartan treatment decreases Visceral Fat Accumulation and improves Serum Levels of Adiponectin and Vascular Inflammation Markers in Japanese Hypertensive Patients.
- The Effects of Verapamil SR and Bisoprolol on Reducing the Sympathetic Nervous System's Activity.
- The Role of Renal Dopamine in the Reduction of High Blood Pressure by β1-Selective β-Blocker with Intrinsic Sympathomimetic Activity in Spontaneously Hypertensive Rats
- Effects of Long-Term Antihypertensive Therapy on Physical Fitness of Men with Mild Hypertension.
- Prediction of Progression of Left Ventricular Hypertrophy in Mild Hypertension: 5-Year Observations without Pharmacological Intervention.