US EPA

2312333 

Journal Article 

Effects of protein-deficient nutrition during pregnancy and development on developmental hindlimb crossing due to methylmercury intoxication 

Chakrabarti, SK; Bai, C 

2000 

1 

Toxicologist
ISSN: 0731-9193 

DART/TER/20000228 

54 

1 

eng 

The effects of methyl mercury intoxication on the clinical neurological signs due to protein-calorie malnutrition in children are not known sufficiently. Timed pregnant Sprague-Dawley rats were fed either a control (20% protein) or low (3.5% protein) diet during gestation and lactation. The pups were separated from their mothers of each diet group on postnatal day 21, and were given the same diets as those of their corresponding mothers. The groups of pups from each diet group were treated either on postnatal day 21, or postnatal day 60 with 7.5 mg methylmercury chloride (MeHgCl) per kg b.w. once daily by gavage for 10 consecutive days and the development of ataxia (hind limb crossing) was monitored. The offspring from protein-deficit diet were found to be more sensitive to MeHg-induced ataxia than those from protein-sufficient diet. Rats fed 3.5% casein diet accumulated more mercury in the different brain regions than those fed 20% casein diet. The rates of protein synthesis in different brain regions of offspring fed the protein-deficient diet were significantly reduced compared to those fed the protein-sufficient diet. However, MeHg treatment did not significantly modify further the rates of such protein synthesis in protein-deficient rats. Thus, increased inhibition of the rates of protein synthesis plus increased accumulation of mercury in different brain regions due to severe protein deficiency may result in increasing susceptibility of developing rats to MeHg-induced ataxia, or hind limb crossing.