Effects of the diabetes mellitus in the metabolism of the catecholamines in rat mesangial cells

Abstract

The aim of this study is to analyze the catecholamines (CA) profile in mesangial cells (MC) from normal and diabetic animals. The diabetes mellitus has been induced in Wistar‐Hannover by injection of streptozotocin (50mg/kg). Three groups of study ‐ Control (CT), Hyperglycemic (HG) and treated Diabetic (TD), were evaluated during 60 days. MCs were obtained through sieve fractionation and collagenase‐treatment, and collected in the third subculture. CA concentrations were determined by high performance liquid chromatography. CA concentrations in the MC extracellular medium (EM) and intracellular compartment (IC) of the CT group expressed in pg/mg of cellular protein were respectively: Norepinephrine (NE), 18.1±1.1; Epinephrine (EP), 10.0±0.6; Dopamine (DE), and NE, 117.3±10.1; AD, 62.6±9.4; DE, 39.1±7.7. The levels of CA detected for HG in the EM were NE, 43.5±5.8; EP, 149.0±33.6; DE, 57.9±11.2 and in the IC were NE, 109.4±41.3; EP, 269.6±22,3; DE, 189.1±48.9. The comparison between groups demonstrated statistically significant differences in the CA levels of TD‐HG and for CT‐HG (TD and CT had a similar behavior). Thus, we can suggest that besides the renal damage induced directly by high blood glucose levels, DM could disturb CA metabolism and contribute to the development of diabetic nephropathy. Supported by FAPESP 02/13290‐2.