Vitamin D metabolism impairment in the rat's offspring following maternal exposure to 137cesium.
Previous works clearly showed that chronic contamination by 137cesium alters vitamin D metabolism. Since children are known to be a high-risk group for vitamin D metabolism disorders, effects of 137Cs on vitamin D biosynthetic pathway were investigated in newborn rats. The experiments were performed in 21-day-old male offspring of dams exposed to 137Cs in their drinking water at a dose of 6,500 Bq/l (150 Bq/rat/day) during the lactation period. Significant modifications of blood calcium (-7%, P < 0.05), phosphate (+80%, P < 0.01) and osteocalcin (-25%, P < 0.05) levels were observed in contaminated offspring, associated with an increase of blood vitamin D3 (+25%, P < 0.01). Besides, decreased expression levels of cyp2r1 and cyp27b1 (-26 and -39%, respectively, P < 0.01) were measured in liver and kidney suggesting a physiological adaptation in response to the rise in vitamin D level. Expressions of vdr, ecac1, cabp-d28k, ecac2 and cabp-9k involved in renal and intestinal calcium transport were unaffected. Altogether, these data show that early exposure to post-accidental doses of 137Cs induces the alteration of vitamin D metabolism, associated with a dysregulation of mineral homeostasis.
Tissandie
E
E
Radiological Protection and Human Health Division, Radiobiology and Epidemiology Department, Laboratory of Experimental Toxicology, Institute for Radiological Protection and Nuclear Safety, BP n(o) 17, 92262 Fontenay-aux-Roses Cedex, France.
Guéguen
Y
Y
Lobaccaro
J M A
JM
Grandcolas
L
L
Grison
S
S
Aigueperse
J
J
Souidi
M
M
D015090:25-Hydroxyvitamin D3 1-alpha-Hydroxylase / Q000235:genetics / Q000378:metabolism / Q000528:radiation effects*; D000818:Animals; D000831:Animals, Newborn; D002118:Calcium / Q000097:blood; D002588:Cesium Radioisotopes / Q000633:toxicity*; D047852:Chernobyl Nuclear Accident; D002762:Cholecalciferol / Q000097:blood; D053493:Cholestanetriol 26-Monooxygenase / Q000235:genetics / Q000378:metabolism / Q000528:radiation effects*; D004326:Drinking; D005260:Female; D015971:Gene Expression Regulation, Enzymologic / Q000528:radiation effects; D007668:Kidney / Q000378:metabolism / Q000528:radiation effects; D007774:Lactation; D008099:Liver / Q000378:metabolism / Q000528:radiation effects; D008297:Male; D018811:Maternal Exposure; D015675:Osteocalcin / Q000097:blood; D010710:Phosphates / Q000097:blood; D051381:Rats; D017207:Rats, Sprague-Dawley; D014807:Vitamin D / Q000378:metabolism*; D014867:Water; D014875:Water Pollutants, Radioactive / Q000633:toxicity*
D002588:Cesium Radioisotopes; D010710:Phosphates; D014875:Water Pollutants, Radioactive; D014867:Water; D015675:Osteocalcin; D014807:Vitamin D; D002762:Cholecalciferol; D053493:Cholestanetriol 26-Monooxygenase; D015090:25-Hydroxyvitamin D3 1-alpha-Hydroxylase; D002118:Calcium