Induction of bone resorption by parathyroid hormone in congenital malignant osteopetrosis

摘要: A male patient, afflicted with malignant congenital osteopetrosis, was studied over a 5 year period. Hypocalcemia (less than 8 mg/dl) lack of an appropriate increase in serum immunoreactive parathyroid hormone (iPTH) prevailed at all times. Under calcium restricted diet, 6-hour infusion extract normalized calcium, and increased the urinary hydroxyproline excretion suggesting that bone resorption had been induced. second attempt to induce made by infusing synthetic amino terminal fragment bovine PTH period 3 weeks dose 1.5 units/kg/hr. This evoked (8.1 10.5 mg/dl), (0.03 0.65 mg/g creatinine) (160 372 creatinine); increases which were reversed calcitonin administration. Iliac crest biopsies obtained before on last day 3-week infusion. Quantitative comparison two specimens showed that, during infusion, there 23% decrease volume due marrow space, 93% number osteoclasts 136% increment osteoclastic surface. Electron microscopic examination first tissue sample no evidence ruffled borders, while biopsy, numerous cytoplasmic processes indicative resorptive activity visible matrix-cell interface. It is proposed our osteopetrotic phenotype consequence abnormality interaction between may be related synthesis physiologically "defective" PTH.