Biochemical Responses in Freshwater Fish Exposed to Insecticide Propoxur.

Although designed to control pests selectively, there is some evidence that environmental contamination by pesticides increases risks for humans and wildlife. In the present study, we evaluated biomarkers of oxidative stress in Astyanax jacuhiensis exposed to (5, 15 and 30 µg L-1) of carbamate Propoxur (PPX) for 96 h. Glutathione S-transferase (GST) in liver and gills showed reduced activity in all PPX concentrations tested. Acetylcholinesterase (AChE) activities reduced in brain and muscle at concentrations 15 and 30 µg L-1 of PPX. Lipid peroxidation (LPO) and hydrogen peroxide (HP) had no significant differences. In the brain, protein carbonyl (PC) increased in all groups treated with PPX. Although PPX is a selective pesticide, it causes oxidative damage and enzyme alteration in fish. This study pointed out some biomarkers that could be used to assess effects of environmentally relevant concentrations of pesticides, and infer about studies using fish as bioindicator.

Effects of prenatal and postnatal exposure to a low dose of bisphenol A on behavior and memory in rats.

Endocrine disruptors (EDs) are increasingly common chemicals in the environment. Bisphenol A (BPA), used to manufacture polycarbonate plastics, is an ED recognized for its estrogenic, anti-estrogenic, and anti-androgenic effects. Behavior is considered a vital characteristic for an animal's life cycle. This study evaluated the effect of exposure to low doses of BPA during pregnancy and/or lactation on several aspects of rat behavior, including memory, locomotion, and the exploratory instinct. Pups at 16 weeks of age (females and males) were divided into groups according to the mother's exposure to BPA (40µg/kg/day): CON (vehicle only); PRE (during pregnancy); LAC (during lactation); PRE-LAC (during both pregnancy and lactation). In the PRE-LAC group, exposure to BPA impaired both short-term (STM) and long-term memory (LTM) in inhibitory avoidance and the object recognition task, and also affected locomotor activity and spatial memory. Some sex-specific behavioral characteristics disappeared in the LAC group. Sex-specific memory and behavior impairment were caused by BPA exposure during brain organogenesis and differentiation.