Dietary vitamin B6 supplementation attenuates hypertension in spontaneously hypertensive rats

In spontaneously hypertensive rats (SHRs) excess endogenous aldehydes bind sulfhydryl groups of membrane proteins, altering membrane Ca2+ channels, in creasing cytosolic free calcium and blood pressure. N-acetyl cysteine norma lizes elevated blood pressure in SHRs by binding excess endogenous aldehyde s. It is known that dietary vitamin B6 supplementation can increase the lev el of endogenous cysteine. Our objective was to investigate whether a dieta ry supplementation of vitamin B6 can prevent hypertension and associated ch anges in SHRs. Starting at 7 weeks of age, animals were divided into three groups of six animals each. Animals in WKY-control group and SHR-control gr oup were given a normal vitamin B6 diet; and SHR-vitamin B6 group, a high v itamin B6 diet (20 times the recommended dietary intake; RDA) for the next 14 weeks. After 14 weeks, systolic blood pressure, platelet [Ca2+](i) and l iver, kidney and aortic aldehyde conjugates were significantly higher in SH R controls compared to WKY controls. These animals also showed smooth muscl e cell hyperplasia in the small arteries and arterioles of the kidneys. Die tary vitamin B6 supplementation attenuated the increase in systolic blood p ressure, tissue aldehyde conjugates and associated changes. These results f urther support the hypothesis that aldehydes are involved in increased syst olic blood pressure in SHRs and suggest that vitamin B6 supplementation may be an effective antihypertensive.