Effect of clenbuterol on tracheal mucociliary transport in horses undergoing simulated long-distance transportation.

This research looks into the effects of clenbuterol, a beta-2 agonist, on the tracheal mucociliary clearance rate (TMCR) in horses during simulated long-distance transport. The study indicates that giving horses clenbuterol can modestly mitigate the adverse effects of long-distance travel on their respiratory systems.

Research Objectives and Methodology

• The objective of this research was to analyze whether clenbuterol could improve the tracheal mucociliary clearance rate (TMCR) of horses during simulated long-distance transport.
• In the study, six adult horses were used. The horses underwent a cross-over designed prospective study and were maintained with a fixed elevated head position for 48 hours to simulate long-distance transport conditions. They were treated with either clenbuterol or a placebo, starting 12 hours before the journey.
• The tracheal mucociliary clearance rate (TMCR) was measured using a charcoal clearance technique. The data collected included measures of TMCR, tracheal wash cytology and quantitative culture, rectal temperature, complete blood count (CBC), fibrinogen levels, and various serum levels.
• The researchers used regression analysis and Wilcoxon rank-sum tests for data analysis and allowed an 18-21 day washout period between study arms.

Key findings

• The research found that tracheal mucociliary clearance rate (TMCR) was significantly decreased after transportation in both the treatment (clenbuterol) and placebo groups. However, the group treated with clenbuterol showed half the reduction in TMCR compared with the placebo, revealing a significant treatment effect.
• The study also found notable differences in serum fibrinogen, peripheral eosinophil count, quantitative culture, tracheal bacteria, and degenerate neutrophils before and after transport. Still, no treatment effect was found for these parameters.
• The findings suggest that the administration of clenbuterol can modestly mitigate the negative impact on the TMCR of horses caused by long-distance transportation.

Conclusions

• Conclusively, this study presents that administration of clenbuterol can modestly alleviate the detrimental effects of long-distance transportation on tracheal mucociliary clearance in horses. However, further research may be needed to explore the potential effects on other health factors that change after transport.