Neurobehavioral and neurochemical effects in rats offspring co-exposed to arsenic and fluoride during development

Abstract

Arsenic (iAs) and fluoride (F) are ubiquitous in the environment. All over the world, in many countries, thousands of people are suffering from the toxic effects of arsenicals ad fluorides. These two elements are recognized worldwide as the most serious inorganic contaminants in drinking water. When two different types of toxicants are simultaneously going inside the human body they may function independently or can act as synergistic or antagonistic to one another. Although there have been reports in literature of individual toxicity of iAs and F, however, not much is known about the effects following the combined exposure to the toxicants above mentioned. In this work, we investigated the effect of the co-exposure to low levels of iAs/F through drinking water during pregnancy and lactation on central nervous system functionality in the exposed rats offspring. Wistar rats were exposed to one of these solutions: 0.05 mg/L iAs and 5 mg/L F (Concentration A) or 0.10 mg/L iAs and 10 mg/L F (Concentration B) from gestational day 0 up to post-gestational day 21. Sensory-motor reflexes a Functional Observational Battery and the locomotor activity in an open field were assessed in offspring. Additionally, the transaminases, acethylcholinesterase and catalase levels in the striatum were determined to elucidate the possible molecular mechanisms involved in locomotor and neurobehavioral disorders. The results showed that iAs/F exposition during development produces a delay reach the maturity of sensorimotor reflexes. A decrease in the nociceptive reflex response, and increase in the locomotor activity in adult rats offspring were observed. The increase in oxidative stress, the inhibition of transaminases enzymes and the inhibition of AChE in the striatum may partially regulate all the neurobehavioral disorders observed.

Keywords: Acetylcholinesterase; Arsenic/Fluoride; Catalase; Development exposure; Motor activity; Striatum; Transaminases.