Análise morfológica e fisiológica dos fígados e rins de ratas prenhes e seus fetos tratados pela associação zidovudina, lamivudina e ritonavir durante toda a prenhez

Abstract

to evaluate the effect of administration of three different doses of the zidovudine/lamivudine/ritonavir combination on the liver and kidneys of pregnant rats and their concepts from a morphological and physiological standpoint. 40 pregnant EPM-1 Wistar rats were randomly divided into 4 groups: 1 control (Ctrl: drug vehicle control, n=10) and 3 experimental groups: Exp1x, Exp3x and Exp9x. An oral solution of the zidovudine/lamivudine/ritonavir combination was administered to the experimental groups from the day 0 to day 20 of pregnancy: Exp1x=10/5/20 mg/kg; Exp3x=30/15/60 mg/kg; Exp9x=90/45/180 mg/kg. On the 20th pregnancy day the rats were anesthetized and blood was taken directly from the ventricular chambers for further biochemical determinations: aspartate-(AST) and alanine-(ALT) aminotransferases (Calorimetric method), urea nitrogen (BUN) by an enzymatic-kinetic method, and creatinine by a kinetic-calorimetric method. Maternal and fetal liver and kidney samples were taken, fixed in 10% formaldehyde and processed histologically for paraffin embedding. Five µm-thick fragments of maternal and fetal livers and kidneys were stained with hematoxilyn-eosin, being analyzed by light microscopy. To interpret the results, the well-known pattern of normality for livers and kidneys was considered on the basis of the following structures: hepatocytes, portal structure, hepatic veins, renal corpuscles, renal tubules and loop of Henle. Regarding the fetal livers, we also considered the erythrocytes in their different stages of development as well as the megacariocytes. If there was a change in the established staining pattern for liver and kidney structures, changes in nuclear morphology, rupture of some cytoplasmic organelles, and presence of vascular congestion, this was considered to be due to the drug doses. Results were submitted to analysis of variance (ANOVA) and to the Tukey-Kramer multiple comparisons test (p<0.05). no morphological changes were observed in the maternal livers of the Ctrl, Exp1x and Exp3x groups. In the maternal liver of the Exp9x group, hepatocytes showed signs of atrophy and apoptosis (eosinophilic cytoplasm and pycnotic nuclei) and marked sinusoid capillary vasodilation (congestion) was observed. The maternal kidneys of the Ctrl and Exp1x groups were normal, with renal corpuscles, convoluted tubules and typical loops of Henle. In contrast, the Exp3x and Exp9x groups showed vascular congestion and small glomeruli rich in cells containing hyperchromatic nuclei which were more intense in Exp9x. Regarding the fetal organs, no morphological or physiological changes were observed. A significant increase of AST (305.70±55.80, p<0.05) and creatinine (0.50±0.09, p<0.05) was observed in group Exp9x. our results show that the administration of the zidovudine, lamivudine and ritonavir combination to pregnant rats at high doses caused morphological and physiological changes in the maternal liver and kidneys. On the other hand, there were no changes in fetal organs.