Biomedical Engineering Reference
In-Depth Information
neurobehavioral deficits (Jones and Smith, 1973). On the other hand,
while prenatal MeOH exposure is developmentally toxic in mice and
rats, the mechanism is unclear, and it is not known whether MeOH is
developmentally toxic in humans. There are several confounding
factors in attempting to compare the embryopathic potencies of
EtOH and MeOH in vivo. In some studies, the maternal peak BAC
achieved in the model may not have been measured, let alone concen-
trations in embryonic or fetal tissues, so it is difficult to compare one
alcohol and dose to another. Additionally, mice of different strains
exhibit varied susceptibility to the same dose of drug such that their
dose-response curves are shifted, with one strain of mouse being more
or less susceptible than another strain under the same experimental
conditions (Chernoff, 1980; Weston et al., 1994). Furthermore, dosing
regimens, routes of administration, as well as outcomes measured differ
across studies, precluding direct comparisons. In vivo studies compar-
ing the same molar equivalent dose of EtOH and MeOH in the same
strains and species under the identical conditions measuring the same
developmental endpoints and at least the peak maternal BAC, if not
embryonic or fetal tissue concentrations, would be useful in determin-
ing more definitively the relative teratological potencies of these two
alcohols.
7.3.3 Neurodevelopmental Effects
FASD in humans resulting from EtOH exposure during pregnancy may
include neurodevelopmental effects, such as cognitive and other behav-
ioral deficits (Jones, 2011). Behavioral deficits as a result of in utero
MeOHexposure remain to be definitively determined owing to the lack of
reports in humans and investigations in animal models. Only Long-Evans
rats given either MeOH in drinking water (GDs 15-17 or 17-19) or
inhaled MeOH (GD 7-19) during pregnancy have been studied for
postnatal behavioral and cognitive deficits (Infurna and Weiss, 1986;
Stanton et al., 1995) (Table 7.9). The first study monitored litter parame-
ters such as litter size, fetal weight, and infant mortality, as well as eye
opening, suckling, and nest-seeking (homing) behavior. Pups exposed to
MeOH required more time to suckle on postnatal day (PND) 1 and also
