Effectiveness of dexamethasone and doxorubicin in Ehrlich tumor of as transplanted in mice BALB/c / Eficácia da dexametasona e da doxorrubicina no tumor de Ehrlich transplantado em camundongos BALB/c




Every year, thousands of new cases of cancer appear all around the world in human beings. In Brazil around 460.000 are notified every year. In the veterinary medicine an increase of the cases of neoplasics has been noted, mainly among the pets, due to elevation of the expectative of life in dogs and cats. These aspects show the necessity to study and to implant new protocols for treatment of these tumors. The discovery of the transplantation of the tumors favoured the study of the behaviour of several cancers. The Ehrlich ascites tumor (EAT), was the model used in mice BALB/c inoculated with this tumor in the interescapular subcutaneus region, growing in the solid form, to evaluate the behaviour chemotherapyc of the dexamethasone (DEX) and doxorubicin (DOX) used into the lesion. DEX was used in 0,1mg/cm and 0,2mg/cm of tumoral mass to each 48 h in three applications. DOX was used in two doses of 25mg/m with intervals of 15 days between the two applications. These chemotherapycs were also studies "in vitro" in the cell culture of TAE, being DEX in the concentrations of 1 and 2 M and DOX in the 0,5mg/ml and 1,0mg/ml of complete RPMI-1640 medium. To verify the percentage of inhibition of the cell growth for the drugs, the times established for the counting of the cells were 1, 2, 3and 24 hours after the drugs administration. The macroscopic reduction of the tumoral mass was evaluated immediately through the measurement with analogical pachemetric before each treatment and after the last chemotherapic section. To histologycal evaluation of TAE after treatments slides were stained with hematoxilin-eosin. The following parameters were observed: density of the cellular population, occurrence of mitosis, apoptotics bodies, and intensity of the inflammatory cells. The detection of the apoptotics bodies was done by the immunofluorescence assay with acridin orange, where the presence of the innumerous apoptotics bodies can be observed in the two treatments. The results of the morphometry of the tumor show a sharp effect of DEX in the reduction of the tumoral mass. In the treatment for DOX did not have macroscopic reduction; however inhibition of growth in the treated group in relation to the control group was noticed. The treatment of the cell culture of TAE showed that DEX has more precocious effect evidencing that these cells possess receptors for glucocorticoid. The cells treated with DOX answered to the treatment after 24 h, confirming the necessity of longer treatment cycles for this tumor. The histologycal analysis after the treatments confirmed the characteristics of this tumor. However, it was not possible to determine if the necrosis occurrence is a natural characteristic of the tumor or if the necrosis increase was an action of the chemotherapycs.


tratamento tumores dexametasona dexamethasone patologia animal doxorubicin treatament doxorrubicina tumors apoptose

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