Our previous studies demonstrated an increased reactive oxygen species (ROS) production, as well as transforming growth factor-beta1 (TGF-beta1) expression in the rat kidney with aging. In the present study, we examined the effect of aging on extracellular matrix (ECM) accumulation and the effects of treatment with angiotensin-converting enzyme inhibitors (captopril and lisinopril) and taurine, an antioxidant amino acid. Age-related increases in types I and IV collagen and fibronectin mRNA expression were found at 24 and 30 mo of age. In contrast, type III collagen only increased in 30-mo-old rats. Captopril-, lisinopril-, and taurine-treated animals showed a statistically significant decrease in ECM protein expression at both ages. Moreover, treatment with taurine reduced the TGF-beta1 mRNA levels in 24- and 30-mo-old rats by 40%. Taurine also completely blocked increases in type I and type IV collagen expression in mesangial cells in response to TGF-beta1. Our results demonstrate a protective role from both converting enzyme inhibitors and taurine in the age-related progressive renal sclerosis. In addition, taking into account that taurine is considered as an antioxidant amino acid, present data suggest a role for ROS in age-related progressive renal fibrosis, perhaps through interactions with the TGF-beta1 pathway.

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Taenia crassiceps cysticerci were disrupted through trypsinization to isolate cells which can be maintained in culture for up to 15 days. When injected intraperitoneally into susceptible BALB/cAnN mice, complete cysticerci were recovered in a number that is proportional to the quantity of injected cells. Thus, cysticerci contain cells which can reconstitute complete cysts, suggesting that individual cells play a role, independent to budding, during asexual multiplication of T. crassiceps cysticerci in the peritoneal cavity of mice. In contrast, injection of the cells into resistant C57BL/6J mice does not result in the recovery of complete cysts. These findings provide a new experimental model to identify resistance factors in the hosts, for the in vitro screening of anti-cysticerci drugs and for the genetic manipulation of cysticerci through recombinant DNA techniques.

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