Lactational exposure to inorganic mercury: evidence of neurotoxic effects.
This study examined the effects of inorganic mercury (mercuric chloride - HgCl2) exposure exclusively through maternal milk on biochemical parameters related to oxidative stress (glutathione and thiobarbituric acid reactive substances levels, glutathione peroxidase and glutathione reductase activities) in the cerebellum of weanling mice. These parameters were also evaluated in the cerebellum of mothers, which were subjected to intraperitoneal injections of HgCl2 (0, 0.5 and 1.5 mg/kg, once a day) during the lactational period. Considering the relationship between cerebellar function and motor activity, the presence of motor impairment was also evaluated in the offspring exposed to HgCl2 during lactation. After treatments (at weaning), pups lactationally exposed to inorganic mercury showed high levels of mercury in the cerebellar tissue, as well as significant impairment in motor performance in the rotarod task and decreased locomotor activity in the open field. Offspring and dams did not show changes in cerebellar glutathione levels or glutathione peroxidase activity. In pups, lactational exposure to inorganic mercury significantly increased cerebellar lipoperoxidation, as well as the activity of cerebellar glutathione reductase. However, these phenomena were not observed in dams. These results indicate that inorganic mercury exposure through maternal milk is capable of inducing biochemical changes in the cerebellum of weanling mice, as well as motor deficit and these phenomena appear to be related to the pro-oxidative properties of inorganic mercury.
Franco
Jeferson L
JL
Departamento de Bioquímica, Centro de Ciências Biológicas, Universidade Federal de Santa Catarina, 88040-900, Florianópolis, SC, Brazil.
Braga
Hugo de Campos
Hde C
Nunes
Adriana K C
AK
Ribas
Camila M
CM
Stringari
James
J
Silva
Aline P
AP
Garcia Pomblum
Solange C
SC
Moro
Angela M
AM
Bohrer
Denise
D
Santos
Adair R S
AR
Dafre
Alcir L
AL
Farina
Marcelo
M
D000818:Animals; D000831:Animals, Newborn; D001921:Brain / Q000378:metabolism; D001923:Brain Chemistry / Q000187:drug effects; D002531:Cerebellum / Q000187:drug effects / Q000378:metabolism; D005260:Female; D005979:Glutathione Peroxidase / Q000378:metabolism; D005980:Glutathione Reductase / Q000378:metabolism; D006305:Health Status Indicators; D007774:Lactation / Q000502:physiology*; D015227:Lipid Peroxidation / Q000187:drug effects; D008297:Male; D008628:Mercury / Q000493:pharmacokinetics; D020262:Mercury Poisoning, Nervous System / Q000473:pathology*; D051379:Mice; D008892:Milk / Q000378:metabolism*; D009043:Motor Activity / Q000187:drug effects; D018384:Oxidative Stress / Q000187:drug effects; D011597:Psychomotor Performance / Q000187:drug effects; D017392:Thiobarbituric Acid Reactive Substances / Q000378:metabolism
D017392:Thiobarbituric Acid Reactive Substances; D005979:Glutathione Peroxidase; D005980:Glutathione Reductase; D008628:Mercury