From 5 weeks of age, stroke-prone spontaneously hypertensive rats (SHRSP) were fed a diet based on Chlorella (Chlorellavulgaris E-25) and were either observed until natural death or sacrificed at 29 weeks of age in order to examine the effects of the alga on blood pressure, incidence of stroke lesions, hypertensive vascular lesions and life-span. The results were as follows: 1) Elevation of blood pressure was depressed from the start of Chlorella feeding, and after 10 weeks of age the blood pressure remained unchanged at 210 to 230mmHg. 2) The average life-span of the Chlorella diet group was remarkably longer than that of the control group. 3) In the Chlorella diet group, depression of plasma renin activity (PRA), reduction of incidence of cerebral stroke lesions, lowering of incidence of hypertensive vascular lesions in the kidneys, testes and adrenals, and depression of decrease in the elastin content in the aorta were recognized. This group also showed fewer changes in electron microscopical findings in the mesenteric arteries. These results demonstrated that the PRA of SHRSP fed the Chlorella diet was just as low as that of normotensive rats (WKY), and that the effects resulted in the inhibition of vascular lesions, and lowering of the incidence of cerebral stroke lesions, thus extending the life-span.
The dietary fiber contents of Lettuce, Celery, Sweet pepper, Cucumber, Spinach, Eggplant and Chinese cabbage commercially available in Tokyo were deterrmined gravimetrically using the partly modified method of Asp et al. involving enzymatic digestion. Recovery tests performed on cellulose powder gave a recovery of 101.5%, and those performed on model samples containing potato starch and casein gave recoveries of 1.73 and 1.02%, respectively, using mixtures of 6: 4 and 8: 2. These results indicated that the digestive ability of enzymes to remove starch and protein in samples was sufficient under the experimental conditions used. The total dietary fiber contents of these vegetables were 1.1-2.3% fresh weight, which were 1.40-1.81 times higher than those obtained by the neutral detergent fiber (NDF) method of Van Soest using the same samples. The results suggested that some components of dietary fiber might be dissolved by the NDF reagent.