[Effect of dietary supply of calcium on thyroid function in rats].
To determine if calcium had a goitrogenic effect on the thyroid function in rats, weanling rats were fed, for three weeks, a diet containing either 0.5 microgram or 0.04 microgram iodine per gram of diet, or an adequate (0.47%) or an excessive (2%) amount of calcium. With an adequate iodine diet, the calcium load did not induce an increase in the weight of the thyroid or a decrease in serum thyroid hormone concentration. However, the rats given a calcium load had a lighter body weight and a lower iodine content in the thyroid tissue; they also had a higher thyroxine (T4) content in the liver and kidney tissues than the rats receiving an adequate calcium diet. With a low iodine diet, the calcium load brought out a decrease in growth and a lower serum triiodothyronine (T3) concentration and liver and kidney T3 contents. These changes suggest that the calcium load might have acted on the thyroid function through an inhibition of T4-T3 conversion in the serum as well as in liver and kidney tissues.
D000818:Animals; D002118:Calcium / Q000494:pharmacology*; D004032:Diet; D004305:Dose-Response Relationship, Drug; D008099:Liver / Q000187:drug effects / Q000378:metabolism; D008297:Male; D051381:Rats; D011919:Rats, Inbred Strains; D013961:Thyroid Gland / Q000187:drug effects / Q000502:physiology*; D013974:Thyroxine / Q000097:blood / Q000378:metabolism; D014284:Triiodothyronine / Q000097:blood / Q000378:metabolism
D014284:Triiodothyronine; D013974:Thyroxine; D002118:Calcium
Effets de l'apport alimentaire en calcium sur la fonction thyroïdienne chez le rat.