A cafeína exerce efeitos positivos sobre a memória tipo episódica em ratos adultos sem influenciar a sobrevivência neural no giro dentado

The caffeine is a mild psychostimulant that has positive cognitive effects at low doses, while promotes detrimental effects on these processes at higher doses. The episodic-like memory can be evaluated in rodents through hippocampus-dependent tasks. The dentate gyrus is a hippocampal subregion in which neurogenesis occurs in adults, and it is believed that this process is related to the function of patterns separation, such as the identification of spatial and temporal patterns when discriminating events. Furthermore, neurogenesis is influenced spatial and contextual learning tasks. Our goal was to evaluate the performance of male Wistar rats in episodic-like tasks after acute or chronic caffeine treatment (15mg/kg or 30mg/kg). Moreover, we assessed the chronic effect of the caffeine treatment, as well as the influence of the hippocampus-dependent learning tasks, on the survival of new-born neurons at the beginning of treatment. For this purpose, we used BrdU to label the new cells generated in the dentate gyrus. Regarding the acute treatment, we found that the saline group presented a tendency to have better spatial and temporal discrimination than caffeine groups. The chronic caffeine group 15 mg/kg (low dose) showed the best discrimination of the temporal aspect of episodic-like memory, whereas the chronic caffeine group 30mg/kg (high dose) was able to discriminate temporal order, only in a condition of greater difficulty. Assessment of neurogenesis using immunohistochemistry for evaluating survival of new-born neurons generated in the dentate gyrus revealed no difference among groups of chronic treatment. Thus, the positive mnemonic effects of the chronic caffeine treatment were not related to neuronal survival. However, another plastic mechanism could explain the positive mnemonic effect, given that there was no improvement in the acute caffeine groups

Protective effect of simvastatin in the cyclophosphamide-induced hemohrragic cystitis in rats

Cyclophosphamide (CYP) is an antineoplastic agent used for the treatment of many neoplastic and inflammatory diseases. Hemorrhagic cystitis is a frequent side effect of CYP. Several studies show that simvastatin has important pleiotropic (anti-inflammatory and immunomodulatory) effects. The purpose of the study was to investigate the effect of simvastatin on bladder, ureter and kidney injury caused by CYP. Methods: Adult male Wistar rats were randomly divided into three groups. The CYP/SIM group received simvastatin microemulsion by gavage during 7 days (10 mg/kg body wt) before the administration of CYP and the CYP/SAL group rats received saline 0.9%. The control rats were not treated. After that, all rats were treated with a single dose of CYP 200 mg/kg body wt intraperitoneally. The rats were killed 24 h after CYP administration. Plasma cytokines (TNF-a, IL-1b, IL-6) were measured by ELISA. Macro and light microscopic study was performed in the bladder, kidney and ureter. Results: In the bladders of CYP/SIMV treated rats edema of lamina propria with epithelial and sub-epithelial hemorrhage were lower than in CYP/SAL treated rats. The scores for macroscopic and microscopic evaluation of bladder and ureter were significantly lower in CYP/SIMV rats than in CYP/SAL rats. The kidney was not affected. The expression of TNF-a, IL-1b and IL-6 was significatly lower in CF/SINV rats (164.8±22, 44.8±8 and 52.4±13) than in CF/SAL rats (378.5±66, 122.9±26 e 123.6±18), respectively. Conclusion: The results of the current study suggest that simvastatin pretreatment attenuated CYP-induced urotelium inflammation and decreased the activities of cytokines

Protective effect of simvastatin in the cyclophosphamide-induced hemohrragic cystitis in rats

Cyclophosphamide (CYP) is an antineoplastic agent used for the treatment of many neoplastic and inflammatory diseases. Hemorrhagic cystitis is a frequent side effect of CYP. Several studies show that simvastatin has important pleiotropic (anti-inflammatory and immunomodulatory) effects. The purpose of the study was to investigate the effect of simvastatin on bladder, ureter and kidney injury caused by CYP. Methods: Adult male Wistar rats were randomly divided into three groups. The CYP/SIM group received simvastatin microemulsion by gavage during 7 days (10 mg/kg body wt) before the administration of CYP and the CYP/SAL group rats received saline 0.9%. The control rats were not treated. After that, all rats were treated with a single dose of CYP 200 mg/kg body wt intraperitoneally. The rats were killed 24 h after CYP administration. Plasma cytokines (TNF-a, IL-1b, IL-6) were measured by ELISA. Macro and light microscopic study was performed in the bladder, kidney and ureter. Results: In the bladders of CYP/SIMV treated rats edema of lamina propria with epithelial and sub-epithelial hemorrhage were lower than in CYP/SAL treated rats. The scores for macroscopic and microscopic evaluation of bladder and ureter were significantly lower in CYP/SIMV rats than in CYP/SAL rats. The kidney was not affected. The expression of TNF-a, IL-1b and IL-6 was significatly lower in CF/SINV rats (164.8±22, 44.8±8 and 52.4±13) than in CF/SAL rats (378.5±66, 122.9±26 e 123.6±18), respectively. Conclusion: The results of the current study suggest that simvastatin pretreatment attenuated CYP-induced urotelium inflammation and decreased the activities of cytokines