| Budget Amount *help |
¥1,800,000 (Direct Cost: ¥1,800,000)
Fiscal Year 1988: ¥600,000 (Direct Cost: ¥600,000)
Fiscal Year 1987: ¥1,200,000 (Direct Cost: ¥1,200,000)
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| Research Abstract |
To elucidate the influences of environmental factors on the development of genetic hypertension, we investigated the effects of diabetes, vibration stress, high NaCl intake and etc. On blood pressure (BP), hemodynamics, mortality, metablolism and hormones in spontaneously hypertensive (SHR) and normotensive Wistar-Kyoto rats (WKY), and their F1. Induction of chemical diabetes led to deaths in SHR alone, with more marked metabolic changes. These suggest that a combination of hypertension and diabetes results in greater influences. Severe diabetes diminished the coronary flow reserve in shr, so adding a greater coronary risk. Even moderate diabetes, if persisted, depressed systolic cardiac functionn in SHR. When vibration stress, alcohol intake, or high salt intake was imposed on chronically, vibration stress clearly increased BP in SHP. Its combination with high salt loading elicited a synergistic effect. The BP and cardiac weight of F1 averaged those of SHR and WKY. BP and cardiac weight scattered in F2 and F3. Interestingly, some of them displayed cardiac hypertrophy despite normotension. Vibration stress produced a moderate BP increase in F1. Long-term therapy with a Ca antagonist or an alpha / beta blocker lowered BP and regressed cardiac hypertrophy in SHR, while reducing baseline hemodynamics and their stress responses. Thus, some environmental factors aggravated genetic hypertension in SHR. In particular, diabetes added a greater cardiovascular risk. These results suggest the necessity of treating environmental factors effectively in hypertension.
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