Response to “Comment on ‘Effects of in Utero Exposure to Arsenic during the Second Half of Gestation on Reproductive End Points and Metabolic Parameters in Female CD-1 Mice’”

Discussion section of our paper, some of the results under our exposure scheme do not recapitulate those observed in other studies. The main difference that could contribute to these discrepancies is that the offspring in our study were fostered to dams that were not exposed to As during gestation. Dams exposed gestationally to As are known to produce lower-quality milk, which can result in weight deficits in their pups (Kozul-Horvath et al. 2012). In contrast, the studies mentioned by Williams and DeSesso left offspring with their As-exposed mothers. It is therefore possible that the impacts of gestational As exposure on milk quality could offset the effects of As on offspring weight gain and vaginal opening. Regarding the lack of a dose response, our study was designed to examine the impact of two specific As doses: 10 ppb (the U.S. Environmental Protection Agency drinking water standard) and 42.5 ppm (tumor-inducing concentration). Dose–response experiments are usually performed to identify either the proper dose for further experiments or the mode of action of a particular chemical (linear, biphasic, or others). Neither of these two parameters were an end point of our study. We do not have an explanation for the different responses between the 10-ppb and 42.5-ppm treatment groups, and further studies are definitely required. Williams and DeSesso further suggest that the control pups in our study may have been unusually small, such that our results reflect a statistical ...
Source: EHP Research - Category: Environmental Health Authors: Tags: Correspondence March 2016 Source Type: research