Biomedical Engineering Reference
In-Depth Information
Cooper et al. (1992) conducted experiments on the effects of an acute
(6-hour) methanol exposure on serum testosterone and pituitary hor-
mone levels in male rats. In addition, these investigators examined the
potential role of animal husbandry on the results observed. Male Harlan
Sprague-Dawley rats at 90 days of age were either acclimated to the
inhalation chambers and handled for 2 weeks prior to beginning expo-
sures or were started on the exposures with no acclimation. Test animals
received a single 6-hour inhalation exposure to 0 (sham air-exposed),
200, 5000, or 10,000 ppm methanol. One group of rats was killed
immediately following exposure and the remaining animals were killed
18 hours later (24 hours after the start of exposure). In the control
groups, serum hormones were generally higher in the nonacclimated
versus the acclimated rats, suggesting an effect of handling on hormone
concentrations. Unlike the results of Cameron et al. (1984), Cooper
et al. (1992) did not observe a change in serum testosterone levels in
either acclimated or nonacclimated rats at 200 ppm methanol. Immedi-
ately following exposure, nonacclimated rats exposed to 5000 ppm
methanol exhibited an apparent
40% reduction in serum LH com-
pared to nonacclimated controls, but acclimated controls had serum LH
levels similar to those measured in acclimated rats exposed to 5000 ppm
methanol. At 24 h, serum testosterone was lower in acclimated rats
exposed to 10,000 ppm methanol but higher in nonacclimated rats
exposed to 5000 ppm. In the second experiment, Cooper et al.
(1992) measured serum methanol, testosterone, LH, and prolactin in
90-day-old male rats immediately after exposure to 5000 ppmmethanol
for 1, 3, or 6 hours. These studies illustrate that, while 1, 3, or 6 hours
methanol exposures can impact rat serum hormone levels, the magni-
tude and direction of changes may depend on the handling of the
animals.
5.3 DEVELOPMENTALTOXICITY
There are no published studies that report developmental toxicity in
humans following methanol exposure. Because of its proposed use as an
alternative automobile fuel in the late 1980s, a number of studies were
