Biomedical Engineering Reference
In-Depth Information
for either 1 day or 1 week, to methanol, ethanol, n-propanol, or
n-butanol. Animals were sacrificed immediately after exposure or after
an 18-hour recovery period and testosterone, LH, and corticosterone
were measured in serum. The data were consistent with the ability of
these aliphatic alcohols to cause a transient reduction in the formation
of testosterone. Except in the case of n-butanol, rapid recovery from
these deficits can be inferred from the 18-hour postexposure data.
Lee et al. (1991) exposed 8-week-old male Sprague-Dawley rats to 0
or 200 ppm methanol, 8 hours/day, 5 days/week, for 1, 2, 4, or 6 weeks
to assess effects on testosterone production. There was no effect on
serum testosterone, gross structure of reproductive organs, or weight of
testes and seminal vesicles. Lee et al. (1991) also studied the in vitro
effect of methanol on testosterone production from isolated testes, but
saw no effect on testosterone formation either with or without stimula-
tion with human chorionic gonadotropin. In another experiment from
the same report, testicular histopathology was evaluated to determine if
methanol exposure produced lesions indicative of changing testosterone
levels; the effects of age and folate status were also assessed. Groups of
4-week-old male Long-Evans rats were given diets containing either
adequate or reduced folate levels. Some rats were exposed to 0, 50, 200,
or 800 ppm methanol starting at 7 months of age while others were
exposed to 0 or 800 ppm methanol at 15 months of age. Methanol
exposures were conducted continuously for 20 hours/day for 13 weeks.
The authors reported that visual toxicity and acidosis developed in rats
that were fed the low-folate diet and exposed to methanol. No methanol-
related testicular lesions or changes in testes or body weight were
evident at 10 months of age in rats that were fed either the folate
sufficient or deficient diet. Likewise, no methanol-induced lesions were
observed in 18-month-old rats that were fed diets with adequate folate.
The incidence but not severity of age-related testicular lesions was
increased in the 18-month-old rats fed with folate-deficient diets.
Observations of subcapsular vacuoles in germinal epithelium were
increased in the 800 ppm group; one rat in the 800 ppm group had
atrophied seminiferous tubules and another had Leydig cell hyperplasia.
The role of folate in the metabolism and toxicity of methanol is
discussed in greater detail later in this chapter.
