Microcystin-LR at sublethal concentrations induce rapid morphology of liver and muscle tissues in the fish species Astyanax altiparanae (Lambari).

The process of eutrophication and consequent proliferation of cyanobacteria in rivers and lakes leads to increasing numbers of harmful algal blooms and higher concentration of toxic metabolites in freshwater bodies. Microcystin is a toxic metabolite produced by cyanobacteria that is frequently detected and can pose health risks to important freshwater species including fish. The aim of the present study was to evaluate the effects of microcystin-LR on the morphology of Astyanax altiparanae's liver and muscle. One hundred (n = 100) Astyanax altiparanae were divided into 5 groups (n = 20) with 24 h and 96 h of microcystin exposition at two doses of 0.5 and 1.0 µg/L. Differences were observed in the microcystin treatment with respect to histopathological analyses including cytoplastic degradation, displacement, and increase in nuclei volume and area of hepatocytes. Hyperemia and dilation of blood capillaries were seen in the liver. There were also observable changes in the size of muscle fibers and muscle inflammation. Our results demonstrate that microcystins can impact the integrity of both tissues even at sublethal concentrations. Low doses of microcystins are therefore sufficient to intoxicate fish livers and muscle tissues.

Quantifying structural modifications of gills of two fish species Astyanax altiparanae (Lambari) and Prochilodus lineatus (Curimbatá) after exposure to biodegradable detergents in urban lake water.

Anthropic actions in rivers and urban lakes are a cause for concern to our ecosystem. The effects on fauna and flora of substances discharged into waterways have become a focus for investigations globally. Biodegradable detergents are widely used in residences and small industries, but little is known regarding the consequences on fish fauna. The objective of the present study was to identify modifications in gill structure in two fish species, Astyanax altiparanae and Prochilodus lineatus, after treatment with water obtained from an urban lake and an exposure to 1 ppm diluted biodegradable detergents (linear alkylbenzene sulfonate). Data demonstrated exposure to urban lake produced various alterations in gill functions such as lamellar fusions, aneurysms, mucous, and chlorine cell proliferation, which may be attributed to the presence of detergents in the water but may also be a consequence of synergetic actions of detergents with other pollutants. Results showed that the levels of NO-2, Na, F-, Cl-, and Fe were significantly higher in urban lake water but in the presence of detergents Ni was also detected. Evidence indicates that biodegradable detergents produce damage to gill functions, which subsequently alters the fish physiology and reduces the ability to cope with stress and survival.

Effect of treatment with simvastatin on bone microarchitecture of the femoral head in an osteoporosis animal model.

The objective of this study was to evaluate the microarchitecture and trabecular bone strength at the distal region of the femur, and its biomechanical properties with simvastatin administration with two different doses in ovariectomized (OVX) rats. Ninety rats were divided into six groups to evaluate treatment with the simvastatin drug (n = 15): SH (Sham surgery), SH-5 (5 mg simvastatin), SH-20 (20 mg simvastatin), OVX, OVX-5, and OVX-20. Euthanasia was performed at three different times, five animals per period: 7, 14, and 28 days. The effectiveness of the treatments was evaluated by mechanical testing and histomorphometric analysis of the femurs. The results of analysis by the linear model of mixed effects showed 20 mg of simvastatin results in increased trabecular bone after 14 days (P = 0.039) of ingestion in ovariectomized animals. However, ingestion of 5 mg of simvastatin is able to sensitize the trabecular bone only at 28 days (P = 0.005) of ingestion. In the mechanical tests stiffness improves within 28 days (P = 0.003). Regarding maximum strength, no statistical differences were observed. According to these results, it can be concluded that for a decrease in oral intake, longer treatment times are required. Microsc. Res. Tech. 79:684-690, 2016. © 2016 Wiley Periodicals, Inc.

The effect of simvastatin treatment on bone repair of femoral fracture in animal model.

The aim of this research was to evaluate the fracture healing area in osteoporotic femur of female rats restrained by stainless steel wire by statin administration in two different doses (5 mg and 20 mg). Ninety female rats were divided into six groups (n = 15): SH, SH-5 mg, SH-20 mg, OVX, OVX-5 mg, and OVX-20 mg. The surgery consisted of the fracture of the left femur bone and stabilization by K-wire and the administration was restricted and weekly controlled in the drinking water. The euthanasia was conducted at three different moments, five animals per period: 7 d, 14 d, and 28 d. Densitometry, zymography, and histological analyses showed a significant difference between some groups. According to these findings, simvastatin promoted a positive action for bone repair, especially in the osteometabolic group treated with 20 mg of the drug.