revised final - Agency for Toxic Substances and Disease Registry ...

MERCURY 149
2. HEALTH EFFECTS
administered to mice by gavage on either Gd 10 or 12 resulted in decreased fetal weight, cleft palate, and
dilation of the renal pelvis (Yasuda et al. 1985).
Thuvander et al. (1996) evaluated the immunomodulation of methylmercury from perinatal exposure in
mice. Offspring from Balb/c mice were exposed to methylmercuric chloride in the diet. Dams (16.0±0.5g)
were exposed to 0 (n=72), 0.5 (n=27), or 5 (n=37) mg Hg/kg for 10 weeks prior to mating, and during
gestation and lactation. Pups were exposed to mercury until day 15 of lactation; thereafter, the pups were
given control milk and control diet. Samples for mercury analysis were collected from the pups on days
22 and 50, and for immunological studies on days 10, 22, and 50. Immunological parameters included
numbers of splenocytes and thymocytes, proportions of lymphocyte subpopulations within the thymus, the
proliferative response of splenocytes to the B-cell mitogen LPS, NK-cell activity of splenocytes, and the
primary antibody response to a viral antigen. Eight pups (n=8NS) were taken from at least three different
litters for the immune function analysis.
No disturbances in the behavior of dams or pups were observed for any of the dose groups. All dams gave
birth to normal sized litters (8–10 animals/litter). The high dose dams did have a small (4%) but
significant increase in body weight (weeks 4, 5, 9 p