1995 Volume 48 Issue 3 Pages 209-215
From 5 weeks of age, stroke-prone spontaneously hypertensive rats (SHRSP) were fed a diet based on dry cells of Euglena (Euglena gracilis Z; at 25% in diet) with enriched docosahexaenoic acid (DHA-Euglena) until natural death or sacrifice at 20 weeks of age, and the effects of the diet on blood pressure, incidence of stroke lesions and life-span were examined. Spontaneous elevation of blood pressure was depressed by the DHA-Euglena diet after the start of feeding, and after 10 weeks of age the blood pressure remained constant at 210 to 230mmHg. The life-span of the DHA-Euglena-fed group was marked longer than that of the control group, and the incidence of cerebral stroke lesions was lower than that in the control rats. On the other hand, a defatted Euglena diet (at 20% in diet) exerted little effect on blood pressure, but obvious prolongation of life-span was observed. Suppression of aortic hypertrophy was recognized in SHRSP fed the DHA-Euglena diet, and a high level of aortic elastin was maintained. The activities of angiotensin I-converting enzyme (ACE) in the thoracic aorta and mesenteric artery were lower in the DHA-Euglena group than in the control group (p<0.05). The lipid peroxide (TBARS) level and activities of related enzymes in the blood of the DHA-Euglena group showed no difference from those in the control group. Prevention of blood pressure elevation, reduction of the incidence of cerebral stroke lesions and prolongation of life-span in SHRSP were more evident after feeding with DHA-Euglena than with ordinary Euglena. These results indicate that Euglena rich in DHA has an augmented suppressive effect against hypertensive disease in SHRSP.
