Short-term effects of synthetic human parathyroid hormone-(1--34) administration on bone mineral metabolism in osteoporotic patients.

Abstract

A B S T R A C T Since studies in animals and humans have shown that parathyroid hormone can stimulate bone formation and increase trabecular bone, and patients with primary and secondary hyperparathyroidism may exhibit osteosclerosis, we evaluated the effect of short-term administration of human parathyroid hormone, hPTH-(1-34), in patients with osteoporosis.Six patients with osteoporosis underwent detailed studies including blood and urinary measurements of calcium, phosphate, and magnesium; 47Ca kinetic studies; and 18-d balance studies before and during the short-term administration (3-4 wk) of a daily subcutaneous injection of hPTH fragment 1-34 given as 450 or 750 U/dose.The mean fasting plasma calcium values rose slightly after hPTH-(1-34) administration, primarily in the high-dose group. There was no difference in the mean fasting plasma inorganic phosphate levels. The mean daily urinary excretion of calcium and phosphate was significantly increased in patients given the higher dose.In patients given 450 U, net intestinal calcium absorption increased, phosphate absorption increased, calcium balance improved, and phosphate balance improved. In patients given 750 U, calcium balance and phosphate balance worsened.47Ca kinetic studies showed a minimal increase in bone accretion rate, a decrease in the mean transit time of calcium in the exchangeable pools, and a decrease in the exchangeable-pool size. In all six patients there was an increased renal clearance of 47Ca as a result of hPTH-(1-34) administration.These studies indicate that low doses of parathyroid

Circulating Levels of Biologically Active and Immunoreactive Intact Parathyroid Hormone in Human Newborns

“…Low doses of PTH are known to stimulate bone formation in human adults (50,51) and act as a mitogen for embryonic chondrocytes in vitro (52). Therefore, the maintenance of slightly elevated bioPTH levels in the fetal circulation, despite ambient hypercalcemia, suggests a potential anabolic role for the fetal skeleton.…”

Effects of parathyroid hormone on Wnt signaling pathway in bone

“…Parathyroid hormone (PTH) plays a central role in the regulation of bone and mineral metabolism [Reeve et al, 1980;Slovik et al, 1981;Hock et al, 1989a,b;Riggs and Melton, 1992;Dempster et al, 1993;Oxlund et al, 1993;Sato et al, 1997;Jerome et al, 1999]. PTH actions on bone formation are associated with an increase in osteoblast activity, increased differentiation of osteoblast-precursors, recruitment of lining cells, and increased osteoblast survival [Dobnig and Turner, 1995;Onyia et al, 1995Onyia et al, , 1997Jilka et al, 1999].…”

Parathyroid hormone in the treatment of involutional osteoporosis: Back to the future

“…However, most of the trials performed until now should be considered as preliminary since they were too small or insufficiently controlled to establish efficacy definitively [70]. Short-term administration of 100 /lg/ day (450 u/day) of PTH (1-34) improved calcium balance in osteoporotic patients whereas 750 u/day worsened it [71]. In a multicenter trial, 450 u/day ofPTH were given to osteoporotic subjects of both genders, by subcutaneous injection for 6-24 months.…”