In vitro and in vivo effects of activated macrophage supernatant on distal limb wounds of ponies.

This study investigates the potential of monokines, produced by activated rabbit macrophages, to inhibit tissue overgrowth in wounds on pony legs. The researchers found the monokines capable of limiting cell proliferation in vitro, yet observed no significant effects in vivo.

Research Methods

• The study utilized 5 male ponies, aged between 2 and 6 years, and weighing between 140 to 190 kg.
• The in vitro effect of the macrophage supernatant, a byproduct of activated rabbit peritoneal macrophages, was assessed by incubating it with fibroblasts from horse and pony flanks and distal limbs.
• The proliferation of these fibroblasts was measured using tritiated thymidine, a radioactive substance. After reincubation, the radioactivity level was measured, serving as an indicator of cellular proliferation.
• For the in vivo experiment, the researchers created a full-thickness wound on the dorsal aspect of each metacarpus and metatarsus in each pony.
• The effect of the macrophage supernatant on wound healing was evaluated by inspecting biopsy specimens taken at 4, 6, and 10 weeks post-wounding.
• Treatment effects were assessed based on several factors: presence of exuberant granulation tissue (i.e., overgrown tissue in wound), number of times tissue extraction was necessary, total wound area, area of epithelialization, area of granulation bed, and a histological evaluation of the biopsy specimens.

Results and Conclusion

• The researchers discovered that the activated macrophage supernatant could effectively inhibit the proliferation of equine fibroblasts in vitro.
• However, no significant in vivo treatment effects were apparent among the four treatment groups within the pony cohort.
• Despite the lack of noticeable in vivo effect, the researchers concluded that monokines, produced by activated rabbit macrophages, potentially hold promise for improving wound healing in horses and ponies due to their observed inhibitory effect on equine fibroblast proliferation in vitro.