Beneficial effects of the activation of the Angiotensin-(1-7) MAS receptor in a murine model of adriamycin-induced nephropathy

Angiotensin-(1-7) [Ang-(1-7)] is a biologically active heptapeptide that may counterbalance the physiological actions of angiotensin II (Ang II) within the renin-angiotensin system (RAS). Here, we evaluated whether activation of the Mas receptor with the oral agonist, AVE 0991, would have renoprotective effects in a model of adriamycin (ADR)-induced nephropathy. We also evaluated whether the Mas receptor contributed for the protective effects of treatment with AT1 receptor blockers. ADR (10 mg/kg) induced significant renal injury and dysfunction that was maximal at day 14 after injection. Treatment with the Mas receptor agonist AVE 0991 improved renal function parameters, reduced urinary protein loss and attenuated histological changes. Renoprotection was associated with reduction in urinary levels of TGF-{beta}. Similar renoprotection was observed after treatment with the AT1 receptor antagonist, Losartan. AT1 and Mas receptor mRNA levels dropped after ADR administration and treatment with losartan reestablished the expression of Mas receptor and increased the expression of ACE2. ADR-induced nephropathy was similar in wild type (Mas(+/+)) and Mas knockout (Mas (-/-)) mice, suggesting there was no endogenous role for Mas receptor activation. However, treatment with Losartan was able to reduce renal injury only in Mas(+/+) , but not in Mas (-/-) mice. Therefore, these findings suggest that exogenous activation of the Mas receptor protects from ADR-induced nephropathy and contributes to the beneficial effects of AT1 receptor blockade. Medications which target specifically the ACE2/Ang-(1-7)/Mas axis may offer new therapeutic opportunities to treat human nephropathies

Objective assessment of the cryoprotective effects of dimethylformamide for freezing goat semen

AbstractThe aim of this work was to assess the cryoprotective effects of dimethylformamide (DMF) for freezing goat semen, using an objective analysis by computer-assisted sperm analysis (CASA). Twenty-one ejaculates (seven per animal) were collected from three stud bucks with the aid of an artificial vagina and immediately evaluated for gross and microscopic characteristics. The semen was diluted in two steps with a Tris–egg yolk extender containing 6% glycerol or 6% DMF, frozen in 0.50-mL straws, and stored in liquid nitrogen. Samples were accessed for sperm morphology, sperm membrane structural and functional integrity, and by CASA, immediately after thawing. There were differences (P<0.05) between glycerol and DMF with regard to subjective progressive motility (23.9±2.2% vs. 16.6±2.0%), objective progressive motility (3.5±0.4% vs. 1.8±0.3%), linearity (53.9±1.6% vs. 48.1±1.4%) and amplitude of lateral head (2.3±0.1 vs. 2.9±0.1mm), which confirmed the efficiency of glycerol. In conclusion, dimethylformamide could be used as an alternative cryoprotectant for goat semen freezing. However it was showed that no benefits were derived by using dimethylformamide to replace glycerol at an equal 6% concentration