Efeitos da suplementação oral com L-arginina e L-glutamina sobre a próstata ventral de ratos submetidos à irradiação

Abstract

The aim of this study was to investigate the possible protective effect of L-glutamine and Larginine on the rat ventral prostate when administered by gavage. We tried to simulate the clinical conditions of patients undergoing pelvic radiotherapy as with other pelvic organ target organ than the prostate. We analyzed the effects of irradiation on prostate considering this organ as normal. Wistar rats were divided into four groups: Control, animals not exposed to irradiation (n= 10); Irradiated, submitted to abdominal irradiation and without additional amino acid supplementation (n= 10); Irradiated + L-glutamine, submitted abdominal irradiation and additional supplementation with L-glutamine for 21 days (n= 10), and Irradiated + L-arginine, underwent abdominal irradiation and additional supplementation with L-arginine for 21 days (n=9). The groups were kept under standard laboratory conditions during all stages of the experiment. The animals underwent abdominal irradiation received a single dose of 1000 cGy in eight days of trial. L-glutamine and L-arginine were dissolved in distilled water and administered by gavage needle through the IC-810 ®. The prostates were removed and processed for paraffin embedding. We studied the following parameters: acinar structure (area of acini and epithelial height) and collagen analyzed by morphometric methods and body weight. Weight gain in the supplemented groups was significantly higher compared to the irradiated group. There was a reduction in epithelial height in the irradiated group compared to control. The height of the epithelium in the group supplemented with L-arginine was significantly higher than in irradiated and supplemented with L-glutamine. There was a decrease of approximately 18% of the area of the lobes in the group supplemented with L-glutamine. In the group supplemented with Larginine was similar to the value of control. The effect of L-glutamine on the prostatic parenchyma was to keep the collagen in proportion, preserving the integrity of the extracellular matrix. In the group supplemented with L-arginine, despite a slight reduction in the proportional distribution of this collagen also maintained similar levels to the control. The abdominal radiation caused some structural changes in rat ventral prostate. These modifications can be partially prevented by oral supplementation with L-glutamine and L-arginine.