Acrolein is a urinary metabolite of cyclophosphamide and ifosfamide, which has been reported to be the causative agent of hemorrhagic cystitis induced by these compounds. A direct cytotoxic effect of acrolein, however, has not yet been demonstrated. In the present study, the effects of intravesical injection of acrolein and mesna, the classical acrolein chemical inhibitor, were evaluated. Male Swiss mice weighing 25 to 35 g (N = 6 per group) received saline or acrolein (25, 75, 225 µg) intravesically 3, 6, 12, and 24 h before sacrifice for evaluation of bladder wet weight, macroscopic and histopathological changes by Gray's criteria, and 3 and 24 h for assessment of increase in vascular permeability. In other animals, mesna was administered intravesically (2 mg) or systemically (80 mg/kg) 1 h before acrolein. Intravesical administration of acrolein induced a dose- and time-dependent increase in vascular permeability and bladder wet weight (within 3 h: 2.2- and 21-fold increases in bladder wet weight and Evans blue dye exuded, respectively, at doses of 75 µg/bladder), as confirmed by Gray's criteria. Pretreatment with mesna (2-mercaptoethanesulfonic acid), which interacts with acrolein resulting in an inactive compound, inhibited all changes induced by acrolein. Our results are the first demonstration that intravesical administration of acrolein induces hemorrhagic cystitis. This model of acrolein-induced hemorrhagic cystitis in mice may be an important tool for the evaluation of the mechanism by which acrolein induces bladder lesion, as well as for investigation of new uroprotective drugs.

RESUMO O objetivo desse trabalho foi avaliar in vitro a sensibilidade de zigotos murinos à Brucella abortus, a fim de estabelecer um modelo acessível para o estudo de interações embriões-patógenos. Para a coleta dos zigotos, foram utilizados camundongos fêmeas (Swiss Webster) acasaladas com machos inteiros, após superestimulação ovariana. Para a infecção foi utilizada a bactéria B. abortus 1119.3 e a suspensão foi preparada no momento da inoculação (diluição de 106 bactérias/mL). Os zigotos foram separados em controle e infectados (30 µL da suspensão de bactérias), e após 24 e 96h foram analisados quanto à morfologia e taxa de clivagem. No grupo controle não foram verificadas alterações morfológicas, já no infectado foi possível verificar a presença de blastômeros irregulares, falha de divisão, citoplasma com granulação e aspecto degenerativo. As taxas de clivagem após 24h foram de 77,4% (controle) e 59,2% (infectados) (χ2 de 0,001674; p < 0,05) e após 96h de infecção 14,5% (controle) e 7% (infectados) (χ2 de 0,141616; p < 0,05). Considerando os resultados pode-se concluir que os zigotos murinos são sensíveis à B. abortus após exposição in vitro. Provavelmente os zigotos murinos possam ser utilizados como modelo experimental, de baixo custo e fácil acesso, para estudos da interação embrião-B. abortus.

ABSTRACT The aim of this study was evaluate in-vitro the susceptibility of mouse zygotes to Brucella abortus, with the purpose of establishing an accessible model for embryo-pathogen interaction studies. The female mice (Swiss Webster) were superovulated and mated with fertile males of the same strain, and then the zygote retrieval was performed. The bacterial suspension was prepared at the moment of inoculation, and the dilution was 106 brucellas/mL. The zygotes were divided into control and infected groups (30 µL of the bacterial suspension); after 24 and 96h their morphology and viability were analyzed. Morphological changes were not observed in the control group, but the infected one presented irregular blastomers, defective cleavage, granular cytoplasm with degenerative-like morphology. The cleavage rates were 77.4% (control) and 59.2% (infected) (χ2 de 0.001674; p< 0.05) after 24h, and after 96h 14.5% (control) and 7% (infected) (χ2 de 0.141616; p < 0.05). According to the data, mice zygotes are susceptible to B. abortus in-vitro infection. Probably they could be used as an efficient and accessible experimental model for studies of embryo-pathogen interactions.

Plant extracts containing furocoumarins compounds were identified by using melanin producer strains of Nocardiopis sp (DAUFPE-361) and non producer strains of Streptomyces sp (DAUFPE-87). Ethanol, methanol and acetone extracted compounds from conduru (Brosimum gaudichaudii) bark and stem were evaporated and added to tubes containing ISP7 medium (tyrosine agar). This medium was inoculated with spore suspension (10(6)-10(7) CFU) prepared from the different actinomycetes strains. The ethanol fraction (pH 9.0) from both bark and stem induced pigmentation in actinomycetes melanin non producer strains and increased the pigmentation in producer strains indicating presence of furocoumarins in the correspondent plant extracts.