Dietary vitamin C supplementation lowers blood pressure in spontaneously hypertensive rats.
In spontaneously hypertensive rats (SHRs) excess endogenous aldehydes bind sulfhydryl groups of membrane proteins, altering membrane Ca2+ channels and increasing cytosolic free calcium and blood pressure. The thiol compound, N-acetyl cysteine, normalizes elevated blood pressure in SHRs by binding excess endogenous aldehydes. Vitamin C can increase tissue cysteine and glutathione levels. The aim of the present study was to investigate whether a dietary supplementation of vitamin C can lower tissue aldehydes and blood pressure and normalize associated biochemical and histopathological changes in SHRs. Starting at 12 weeks of age, animals were divided into 3 groups of 6 animals each. Animals in the WKY-control group and SHR-control group were given a normal diet and the SHR-vitamin C group a diet supplemented with vitamin C (1000 mg/kg feed) for the next 9 weeks. After nine weeks, systolic blood pressure, platelet [Ca2+]i, plasma insulin and liver, kidney and aortic aldehyde conjugates were significantly higher in SHR controls as compared to WKY controls and the SHR-vitamin C group. SHR-controls also showed smooth muscle cell hyperplasia in the small arteries and arterioles of the kidneys. Dietary vitamin C supplementation in SHRs lowered the systolic blood pressure, tissue aldehyde conjugates and attenuated adverse renal vascular changes.
Vasdev
S
S
Department of Medicine, Health Sciences Centre, Memorial University of Newfoundland, St. John's, Canada.
Ford
C A
CA
Parai
S
S
Longerich
L
L
Gadag
V
V
D000447:Aldehydes / Q000378:metabolism; D000818:Animals; D000975:Antioxidants / Q000494:pharmacology*; D001205:Ascorbic Acid / Q000494:pharmacology*; D001792:Blood Platelets / Q000378:metabolism; D001794:Blood Pressure / Q000187:drug effects*; D001835:Body Weight / Q000187:drug effects; D002118:Calcium / Q000097:blood; D019587:Dietary Supplements; D004326:Drinking / Q000187:drug effects; D004435:Eating / Q000187:drug effects; D006965:Hyperplasia / Q000473:pathology; D006973:Hypertension / Q000188:drug therapy* / Q000473:pathology; D008099:Liver / Q000187:drug effects* / Q000378:metabolism; D009929:Organ Size / Q000187:drug effects; D051381:Rats; D011918:Rats, Inbred SHR; D011921:Rats, Inbred WKY
D000447:Aldehydes; D000975:Antioxidants; D001205:Ascorbic Acid; D002118:Calcium