Efeitos farmacológicos da suplementaçao dietética com arginina em ratos com tumor sólido de walker 256 / Pharmacological effects of arginine supplementation in rats walker 256 solid tumor

Os efeitos da suplementaçao com arginina na dieta de portadores de cancer sao controversos. O objetivo deste trabalho é avaliar os efeitos da suplementacao dietética com arginina no crescimento tumoral, disseminaçao metastática, metabolismo de aminóacidos, alteraçoes hematológicas, tempo de sobrevida e peso corporal de ratos Wistar com tumor sólido de Walker 256. Foram administradas soluçoes por via gástrica, contendo arginina nas concentraçoes de 4 por cento, 6 por cento e dieta padrao (controle). A suplementacao com arginina inibiu a desseminaçao de células tumorais no modelo experimental, embora crescimento tumoral nao tenha sido afectado significantemente. O tempo de sobrevida dos animais com tumor sólido nao foi afetado de forma significativa. Foi observado disminuiçao significativa de peso corpóreo após a administraçao da arginina a 6 por cento (p<0.05). O metabolismo dos aminóacidos foi estimulado após ingestao de suplementos com arginina, evidenciado pelos aumentos significativos dos níveis sanguíneos de arginina, ornitina, citrulina, prolina e histidina quando comparados ao grupo controle (p<0.001). O grau de anemia no tumor sólido foi menos severo nos grupos que receberam suplementaçao com arginina, evidenciado através do hemograma (p<0.001) e da análise citológica. Os resultados sugerem que a suplementaçao dietética com arginina a 6 por cento apresentou algum efeito benéfico no tumor sólido de Walker 256 que ultrapassa o efeito nutricional

Therapeutic trial in experimental tegumentary leishmaniasis caused by Leishmania (Leishmania) amazonensis. A comparative study between mefloquine and aminosidine.

One hundred and eighty-two male inbred C57/BL/6 mice were infected with 3 x 10(6) Leishmania (Leishmania) amazonensis promastigotes of the MHOM/BR/PH8 strain by means of a subcutaneous injection in the right ear. The animals were separated in three groups: 1) oral mefloquine hydrochloride treatment (16 mg/kg/day/10 days), 2) intramuscular aminosidine (Paromomycin) treatment (20 mg/kg/20 days) and 3) control. Twenty-six mice of each treated group were sacrificed, one at the end of treatment (nine weeks after inoculation), and one six weeks later (fifteen weeks after inoculation). Control Group animals were sacrificed at weeks six, nine and fifteen after inoculation. There was no significant difference between Group 1 (mefloquine) and Group 3 (control) subjects. Group 2 animals (aminosidine) presented the smallest differences of all, both at the end of the treatment and six weeks later. The histopato-logical parameters have shown the following findings: a) there was no significant difference between the mefloquine treated group and the control group; the group treated with aminosidine showed fewer of vacuolated macrophages than the control group, at week 9 (end of treatment). b) both at the end of treatment and six weeks later, evaluation of tissue necrosis and tissue fibrosis revealed no differences between the treated groups. It was found that six weeks after the end of treatment, mice in the control group presented significantly more severe degrees of fibrosis than mice in the other groups. It can be concluded that mefloquine showed limited therapeutic effect in this experimental model, whereas aminosidine had a significant effect. Nevertheless, neither of them resulted in cure of the lesions.

[Pharmacological effects of arginine supplementation in rats with Walker 256 solid tumor]. / Efeitos farmacológicos da suplementação dietética com arginina em ratos com tumor sólido de Walker 256.

The effects of diet arginine supplementation for those with cancer are controversial. We evaluate the effects of dietetic supplementation with arginine over body weight, growth of tumor, metastatic dissemination, surviving time, amino acid metabolism, haematological changes of the rats with Walker 256 solid tumor. Intragastrical solutions with arginine at 4% and 6%, a standard diet (control) were administered to the animals. The supplementation with arginine was associated with a lower weight gain during the study period (p < 0.05). Surviving time of the rats with solid tumor did not vary significantly between the groups. The rate of metastase was lower in animals with Walker 256 solid tumor supplemented with arginine. The amino acid metabolism was estimulate in the animals after arginine supplementation at 4% and 6%, demonstrated by significant increases in blood levels of arginine, ornitine, citruline, proline and histidine when compared to the control group. Anaemia was less severe in the rats with Walker 256 solid tumor that received arginine supplementation. The results suggest that arginine 6% supplementation may have pharmacologic effect in rats with Walker 256 solid beyond the nutritional one.