The aim of this study is to analyze the catecholamines (CA) profile and possible enzymatic modifications in normal rat mesangial cells (MC) comparing with the same cells from animals submitted to experimental Diabetes Mellitus (DM) to verify its contribution for the nephropathy diabetic. The DM has been induced in Wistar–Hannover animals by the administration of streptozotocin (SZ - 50mg/kg). Three groups of study were performed: Control (CT - blood glucose < 150 mg/dL); Hyperglycemic (HG – blood glucose > 300 mg/dL) and treated with Insulin Diabetic (TD - blood glucose < 150 mg/dL).  Arterial Pressure (PA), body weight and blood glucose were measuared for 60 days, and evaluated. MCs were obtained through sieve fractionation and collagenase-treatment, and collected in the third subculture.  CA concentrations were determined by high performance liquid chromatography (HPLC). CT showed constant PA and increased body weight. The HG presented body weight loss explained by the lack of insulin in the insulin-depending tissues. So, in this sense these tissues obtain energy by other mechanisms. The TD had a slight body weigh increase. Both TD and HG animals had the PA increased. The CA concentrations in the MC extracellular medium and intracellular compartment 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),  6.7±0.9; L-DOPA, 21.7±5.2 and NE, 117.3±10.1; AD, 62.6±9.4; DE, 39.1±7.7; L-DOPA, 47.20±5.6. The levels of CA detected for HG in the extracellular medium were NE, 43.5±5.8; AD, 149.0±33.6; DE, 57.9±11.2 and in the intracellular were NE, 109.4±41.3; AD, 269.6±22,3; DE, 189.1±48.9. For the TD group extracellular medium presented NE, 26.9±2.8; AD, 16.6±2,4; DE, 6.9±0,7;L-DOPA, 47.2±5,6 and the intracellular NE, 63.5±6.5; AD, 82.5±9.1; DE, 38.8±9.6; L-DOPA,112.6±11.6. The comparison between groups demonstrated significant differences in the CA levels of TD and HG and for CT and HG (TD and CT had a similar behavior). Thus, we can suggest that the DM complications could contribute for disturbs in the CA metabolism, besides the high blood glucose levels could be responsible for the diabetic nephropathy installation. Supported by PIBIC/CNPq and FAPESP 02/13290-2.