Short-term continuous infusion of human parathyroid hormone 1–34 fragment is catabolic with decreased trabecular connectivity density accompanied by hypercalcemia in C57BL/J6 mice

• DOI: 10.1677/joe.1.06270
• Publication Date: 2005-08-31T17:23:50Z
• Authors: A Iida-Klein; S Shou Lu; R Kapadia; M Burkhart; A Moreno; D W Dempster; R Lindsay
• Keywords: Catabolism

Parathyroid hormone (PTH) stimulates bone resorption as well formation in vivo and organ culture. The catabolic actions of PTH have been recognized patients with hyperparathyroidism, or acute infusion the N-terminal 1-34 fragment human (hPTH1-34). Whereas anabolic daily injection studied both humans mice, on murine remain to be defined. To do this we sought create a model short-term, sustained hyperparathyroidism using osmotic pumps. We treated 10-week-old female C57BL/J6 mice continuous hPTH1-34 (8.1 pmol/0.25 microl per h, equivalent 40 microg/kg day) vehicle for 2 weeks, Alzet Bone mineral density (BMD), serum total calcium, hPTH1-34, mouse intact (mPTH1-84), osteocalcin tartrate-resistant acid phosphatase (mTRAP) activity, microarchitectural variables distal femur were measured. Separately, compared effects intermittent (40 BMD markers. Exogenous was detected only PTH-infused mice. Both treatment markedly suppressed endogenous mPTH1-84, but latter induced hypercalcemia. Daily significantly increased mTRAP, while showed strong trend stimulate slight non-significant increase osteocalcin. There significant differences at all sites between animals same dose hPTH1-34. Micro-computed tomography (muCT) analysis femurs revealed that decreased trabecular connectivity (P<0.05). Thus, response quite different from seen injection. Short-term appears good study mechanisms underlying action