OR-70: Antioxidant supplementation beginning in the prenatal stage delays onset and attenuates severity of hypertension (HTN) in SHR

• Published in: American journal of hypertension 2003-05, Vol.16 (S1), p.32A-32A
• Main Authors: Vaziri, N.D., Zahn, C.D., Sindhu, R.K.
• Format: Article
• Language: English
• Subjects: antioxidant enzymes; NAD(P)H oxidase; oxidative stress
• ISSN: 0895-7061; 1941-7225; 1879-1905
• DOI: 10.1016/S0895-7061(03)00153-5

As with humans with essential HTN, spontaneously hypertensive rats (SHR) are born normotensive and develop HTN later in life (age 4-5 weeks). HTN in SHR and other hypertensive disorders is associated with and, in part, caused by oxidative stress. This study was conducted to test the hypothesis that lifelong antioxidant supplementation beginning at prenatal period may delay the onset and reduce severity of HTN in SHR. To this end, pregnant SHR and their off springs were fed either an antioxidant-fortified diet, (chow containing α-tocopherol 5000 U/Kg, ascorbic acid 500 mg/Kg food, selenium 2.76 ppm, zinc 350 ppm) or regular diet (tocopherol 40 U/Kg, selenium 0.2 ppm, zinc 70 ppm). WKY rats served as controls. Animals were observed for 6 months. Onset of HTN was delayed and severity of HTN was reduced in antioxidant-treated compared with untreated SHR. Markers of oxidative stress i.e., plasma hydrogen peroxide, kidney tissue malondialdehyde and nitrotyrosine were elevated in untreated SHR and were normal in antioxidant-treated SHR. gp91phox and p22phox subunits of NAD(P)H oxidase in the renal cortex were markedly elevated in untreated SHR and partially restored in the treated SHR. The untreated SHR exhibited a mild compensatory upregulation of renal tissue Cu-Zn SOD, catalase and glutathione peroxidase all of which were reduced in antioxidant-treated SHR. Thus, oxidative stress in SHR is accompanied by a marked upregulation of renal superoxide-generating enzyme, NAD(P)H oxidase. Amelioration of oxidative stress with life-long antioxidant supplementation delays onset and attenuates severity of the HTN in SHR.