title: Differential effects of calcium-regulating hormones on bone metabolism in weanling rats orally administered zinc sulfate.
abstract: The effect of calcium-regulating hormones on bone metabolism was investigated in weanling rats orally administered zinc sulfate. Administration of 1,25-dihydroxyvitamin D3 (1,25(OH)2D3 (150 ng/100 g BW) or parathyroid hormone (1-34) (PTH) (10 U/100 g) produced significant increases in alkaline phosphatase activity and DNA content in the femoral diaphysis, while calcitonin (CT) (1.0 U/100 g) did not have a significant effect. Administration of zinc (1.0 mg/100 g) caused a significant elevation of alkaline phosphatase activity and DNA content in the femoral diaphysis. In combination with these hormones and zinc, both 1,25(OH)2D3 and zinc caused a synergistic increase in diaphyseal alkaline phosphatase activity and DNA content, while the combination with zinc and PTH, or zinc and CT did not cause a synergistic increase. The synergistic effects in combination with 1,25(OH)2D3 and zinc were completely inhibited by treatment of mitomycin C (10 micrograms/100 g). Meanwhile, the increase in diaphyseal zinc content following zinc administration was not altered by treatment with 1,25(OH)2D3. These results indicate that zinc synergistically enhances 1,25(OH)2D3-stimulated bone metabolism. This suggests a physiologic significance of zinc in the regulation of bone metabolism.
mesh_terms: D000284:Administration, Oral; D000469:Alkaline Phosphatase / Q000378:metabolism; D000818:Animals; D001842:Bone and Bones / Q000187:drug effects / Q000378:metabolism*; D002116:Calcitonin / Q000494:pharmacology*; D002117:Calcitriol / Q000494:pharmacology*; D004247:DNA / Q000378:metabolism; D004347:Drug Interactions; D008297:Male; D008937:Mitomycins / Q000494:pharmacology; D010281:Parathyroid Hormone / Q000494:pharmacology*; D051381:Rats; D011919:Rats, Inbred Strains; D013431:Sulfates / Q000494:pharmacology*; D015032:Zinc / Q000494:pharmacology*; D019287:Zinc Sulfate
chemical_list: D008937:Mitomycins; D010281:Parathyroid Hormone; D013431:Sulfates; D019287:Zinc Sulfate; D002116:Calcitonin; D004247:DNA; D000469:Alkaline Phosphatase; D002117:Calcitriol; D015032:Zinc