Recombinant equine growth hormone does not affect the in vitro biomechanical properties of equine superficial digital flexor tendon.

The research paper explores the effect of recombinant equine growth hormone (rEGH) on the biomechanical properties of the equine superficial digital flexor tendon (SDFT). The study concludes that administering rEGH to adult Standardbred horses for six weeks doesn’t noticeably alter the biomechanical characteristics of a normal SDFT.

Methodology

• Nine healthy Standardbred horses aged between 6 to 9 years were selected as subjects, all of which had ultrasonographically normal forelimb SDFT.
• The horses were randomly assigned to either a control group (3 horses given sterile water) or the treatment group (6 horses treated with rEGH).
• The rEGH was administered intramuscularly to the treatment group at a dosage of 10 micrograms/kg/day for the first week, and 20 micrograms/kg/day for the remaining 5 weeks.
• After the 6-week treatment period, all horses were euthanized, and their forelimb SDFTs were harvested and stored at -70 degrees Celsius.
• In vitro biomechanical tests were then conducted on these tendons under uniaxial tension. This allowed the researchers to measure variables such as cross-sectional area, maximum load at failure, yield load, ultimate and yield tensile strain, ultimate and yield tensile stress, and stiffness.

Results

• The biomechanical testing revealed no significant differences between the control group and those treated with rEGH. This was true across all tested variables: cross-sectional area, maximal load at failure, yield load, ultimate and yield tensile strain, ultimate and yield tensile stress, or stiffness.
• This suggested that the six-week administration of rEGH did not affect these biomechanical properties of the SDFT in normal adult Standardbred horses.

Conclusions

• Based on the study’s findings, the researchers concluded that the use of rEGH does not modulate the in vitro biomechanical properties of the SDFT in adult Standardbred horses.
• Even though equine growth hormone is known for its potential in repairing damage and promoting growth, in this study, it did not noticeably affect the biomechanical characteristics of the equine SDFT.