Long-term effects of intermittent equine parathyroid hormone fragment (ePTH-1-37) administration on bone metabolism in healthy horses.

The study assesses the impacts of a fragment of equine parathyroid hormone (ePTH-1-37) on bone metabolism in healthy horses. Following a once daily dosage regimen over a period of 120 days, researchers observed no detrimental effects on bone metabolism, which could potentially lead to more extensive clinical investigations in horses with bone resorption issues.

Objective and Methodology

• The study intended to understand the effects of a specific fragment of equine parathyroid hormone (ePTH-1-37) on bone metabolism in horses. This fragment has been recognised as an effective treatment for osteoporosis in humans, thus its efficacy in equines is of great interest.
• The study was conducted on 12 healthy horses over a period of 120 days with the horses divided into equal groups. One group was given a daily subcutaneous injection of ePTH-1-37, while the other group was given a placebo.
• Parameters such as ionized calcium (Ca(++)), total calcium (Ca(T)), inorganic phosphorus, serum equine osteocalcin (eOC), bone-specific alkaline phosphatase, and certain types of collagen were measured in blood samples. Additionally, the bone mineral density (BMD) in specific areas was evaluated using dual X-ray absorptiometry.

Findings and Conclusions

• The study found that 5 hours after ePTH-1-37 administration, blood ionized calcium and plasma total calcium levels were significantly higher compared to those in the placebo group.
• Higher levels of serum equine osteocalcin were also recorded in the ePTH-1-37-treated group at the 90th and 120th day.
• Increased levels of certain types of collagen were observed in the ePTH-1-37 treated group on days 60 and 90.
• An increase in bone mineral density in the horses’ calcaneus was observed in both groups of the study.
• Extended use of ePTH-1-37 showed no negative impacts on bone metabolism in healthy horses. This paves the way for future studies on the application of this treatment in horses suffering from increased bone resorption processes.