ABSTRACT
Leptin is secreted by white adipose tissue and its concentration in plasma is higher in obese than in lean subjects. Recent studies suggest that leptin is involved in cardiovascular complications o f obesity including arterial hypertension. Acutely administered leptin has no effect on blood pressure, probably because it concomitandy stimulates sympathetic nervous system and counteracting depressor mechanisms such as natriuresis and nitric oxide-dependent and -in dependent vasorelaxation. In contrast, chronic hyperleptinemia increases blood pressure because these acute depressor effects are impaired and/or additional nonsympathetic pressor mechanisms appear such as increased production o f endothelin-1, overexpression o f endothelin and angiotensin II receptors in vascular smooth muscle cells, oxidative stress, nitric oxide deficiency and enhanced renal Na+ reabsorption. Clinical studies have demonstrated that plasma leptin concentration is higher in patients with essential hypertension than in normotensive controls independendy o f body weight and the significant positive correlation between leptin and blood pressure was observed in both hypertensive and normotensive subjects. M odulating leptin sensitivity and/or leptin level may be a novel approach in the treatment o f hypertension.
