Assessment of in vivo oxidative stress in hypertensive rats and hypertensive subjects in Tanzania, Africa

Oxidative stress has been reported to be involved in not only cardiovascula r diseases but in hypertension, which is a major risk for cardiovascular di seases. urinary 8-hydroxy-2'-deoxyguanosine (8-OHdG) has been recognized as a sensitive biomarker of oxidative DNA damage and also of oxidative stress . In the present study, we assessed the oxidative stress in human subjects with hypertension and in hypertensive rats. In stroke-prone spontaneously h ypertensive rats at the age of 14 weeks, the excretion of urinary 8-OHdG wa s significantly (p<0.05) increased compared with that in age-matched normot ensive Wistar-Kyoto rats. Next, we investigated the relationship between ox idative DNA damage and cardiovascular risk factors among Tanzanians aged 46 -58 years in a population study carried out in 1998 in at Dar es Salaam, Ta nzania, according to the WHO-CARDIAC Study Protocol. Sixty subjects (male/f emale, 28/32) were selected by SPSS Base 8.0 from those who completed a 24- h urine collection. The 24-h urinary 8-OHdG of the hypertensive subjects (S BP greater than or equal to 140 mmHg and/or DBP greater than or equal to 90 mmHg) was significantly (p<0.05) higher than that of the normotensive subj ects (SBP <140 mmHg and DBP <90 mmHg) after adjusting for age and gender (H ypertensives: 17.31 +/- 2.0 ng/mg creatinine, n=38; Normotensives: 10.10 +/ - 2.64 ng/mg creatinine, n=22). Oxidative stress was thought to be involved in hypertensive subjects and in hypertensive rats.