Comparison of the in vitro anticollagenase efficacy of homologous serum and plasma on degradation of corneas of cats, dogs, and horses.

The research paper examines how fresh serum and plasma from cats, dogs, and horses can be used to protect against collagen degradation in the cornea. The findings suggest that plasma can be an effective alternative to serum in protecting against corneal damage, such as that which occurs in a condition called keratomalacia.

Research Procedures

• To begin with, normal corneas were obtained from recently euthanized dogs, cats, and horses. Likewise, fresh serum and plasma were collected from healthy animals of the same species.
• These samples were then pooled by species and used for in vitro (lab-based) experiments. The corneas were stored at a very low temperature (-80°C) to preserve their condition.
• For the experiments, sections of the corneas were dried, weighed, and incubated in a saline solution, together with clostridial collagenase, an enzyme that breaks down collagen, and either the serum or plasma.
• The extent of corneal degradation was assessed through the percentage of corneal weight loss and the concentration of hydroxyproline, a key component of collagens. This was then compared against positive and negative control samples.

Research Findings

• The experiments showed that both serum and plasma significantly reduced the percentage of corneal weight loss when compared to the positive control samples- those treated with collagenase but without serum or plasma.
• However, there were no major differences in the percentage of corneal weight loss when the corneas were incubated with creature-specific serum or plasma. This was consistent across feline, canine, and equine samples.
• A different pattern emerged when considering hydroxyproline concentrations. Canine serum and plasma significantly reduced these concentrations but feline and equine serums or plasmas did not, which is a contrast to the results for the positive control samples.
• There was a moderate correlation between hydroxyproline concentrations and weight loss for feline corneas, a weak correlation for equine corneas, and no correlation for canine corneas.

Research Conclusion

• From the study, the researchers concluded that there was no marked difference in the efficacy of serum and plasma in protecting against collagen degradation in feline, canine, or equine corneas.
• Plasma, therefore, was considered an acceptable substitute for serum in the topical treatment of keratomalacia, a disease that involves severe corneal melting.