BACKGROUND: In the kidney, 5-hydroxytryptamine (5-HT) and dopamine (DA) are formed by the same enzyme, l-aromatic amino acid decarboxylase, but act on renal function and glomerular structure in an opposite direction. The present study was designed to explore whether rates of renal production of 5-HT relative to that of DA are altered in patients with essential hypertension and microalbuminuria. METHODS: We measured urinary levels of 5-HT and DA, reflecting renal production of 5-HT and DA as well as 24-hour ambulatory blood pressure and urinary albumin excretion in 82 consecutive untreated, essential hypertensives without overt proteinuria. RESULTS: Urinary 5-HT excretion and the ratio of urinary 5-HT to DA were significantly higher in 22 patients with microalbuminuria than in the remaining patients with normoalbuminuria, although urinary DA levels did not differ between the groups. The 24-hour systolic and diastolic blood pressures were also higher in the microalbuminuric group than in the normoalbuminuric group. Multiple regression analysis revealed that urinary 5-HT excretion and 24-hour systolic blood pressure were independently associated with urinary albumin excretion. Furthermore, urinary 5-HT excretion was positively correlated with creatinine clearance as well as blood pressure but tended to be negatively correlated with fractional excretion of sodium. CONCLUSIONS: Renal production of 5-HT is enhanced compared with that of DA in essential hypertensives with microalbuminuria. This imbalance may contribute to the genesis of hypertensive glomerular damage.
BACKGROUND: In the kidney, 5-hydroxytryptamine (5-HT) and dopamine (DA) are formed by the same enzyme, l-aromatic amino acid decarboxylase, but act on renal function and glomerular structure in an opposite direction. The present study was designed to explore whether rates of renal production of 5-HT relative to that of DA are altered in patients with essential hypertension and microalbuminuria. METHODS: We measured urinary levels of 5-HT and DA, reflecting renal production of 5-HT and DA as well as 24-hour ambulatory blood pressure and urinary albumin excretion in 82 consecutive untreated, essential hypertensives without overt proteinuria. RESULTS: Urinary 5-HT excretion and the ratio of urinary 5-HT to DA were significantly higher in 22 patients with microalbuminuria than in the remaining patients with normoalbuminuria, although urinary DA levels did not differ between the groups. The 24-hour systolic and diastolic blood pressures were also higher in the microalbuminuric group than in the normoalbuminuric group. Multiple regression analysis revealed that urinary 5-HT excretion and 24-hour systolic blood pressure were independently associated with urinary albumin excretion. Furthermore, urinary 5-HT excretion was positively correlated with creatinine clearance as well as blood pressure but tended to be negatively correlated with fractional excretion of sodium. CONCLUSIONS: Renal production of 5-HT is enhanced compared with that of DA in essential hypertensives with microalbuminuria. This imbalance may contribute to the genesis of hypertensive glomerular damage.
Authors: José Luis Royo; Daniel Castellano-Castillo; Maximiliano Ruiz-Galdon; María Molina-Vega; Fernando Cardona; Francisco J Tinahones; José C Fernández-García; Armando Reyes-Engel Journal: Mol Genet Genomic Med Date: 2019-11-19 Impact factor: 2.183