Experimental induction of parathyroid adenomas in the rat.
Neonatal inbred Wistar albino rats were given either 5 or 10 microCi radioiodine (131I) within 24 hours of birth. After weaning, animals were placed on diets high, normal, or deficient in vitamin D3 (cholecalciferol) for periods up to 2 years. In animals aged 12 months and older, adenomas were found in 0 of 67 unirradiated controls, in 22 of 67 given 5 microCi 131I, and in 25 of 67 given to microCi 131I. The incidence of tumors in irradiated animals was highest (55%) in those on a low-vitamin D diet and lowest (20%) in those on a high-vitamin D diet. Plasma calcium levels were significantly increased by the high-vitamin D diet, but the low-vitamin D diet did not lead to any significant decrease as compared to the calcium levels of the normal vitamin D diet group. Small but significant calcium increases were found in tumor-bearing animals. These findings indicate that parathyroid tumors in the rat can be induced by radiation and that their incidence is strongly influenced by dietary vitamin D content. The possibility that metabolites of vitamin D3 may influence parathyroid growth and tumor formation directly is discussed.
D000236:Adenoma / Q000209:etiology / Q000473:pathology / Q000503:physiopathology*; D000818:Animals; D005260:Female; D007457:Iodine Radioisotopes / Q000009:adverse effects; D008297:Male; D009374:Neoplasms, Experimental / Q000473:pathology / Q000503:physiopathology; D009381:Neoplasms, Radiation-Induced / Q000473:pathology / Q000503:physiopathology*; D010280:Parathyroid Glands / Q000473:pathology / Q000528:radiation effects*; D010282:Parathyroid Neoplasms / Q000209:etiology / Q000473:pathology / Q000503:physiopathology*; D051381:Rats
D007457:Iodine Radioisotopes