Cellular component of lavage fluid from broilers with normal versus aerosol-primed airways

Area of Science:

• Veterinary Pathology
• Avian Immunology
• Respiratory Physiology

Background:

• Intratracheal lipopolysaccharide (LPS) induces pulmonary hypertension (PH) in broilers.
• Previous studies showed PH induction in commercial broilers and those pretreated with red food colorant #3 and propylene glycol (Red#3+PG), but not in controls.

Purpose of the Study:

• To investigate changes in airway leukocyte number and proportion contributing to LPS-induced PH in broilers.
• To determine if Red#3+PG pretreatment alters the pulmonary inflammatory response to LPS.

Main Methods:

• Broilers were aerosolized with Red#3+PG or control solution.
• Blood samples and pulmonary lavage were collected 24 hours post-aerosolization.
• Leukocyte concentration and differential counts were analyzed in blood and lavage fluid.

Main Results:

• Blood leukocyte concentration did not differ between groups.
• The percentage of blood lymphocytes was lower in the Red#3+PG group.
• Leukocyte concentration in lavage fluid was significantly higher in the Red#3+PG group compared to controls.
• Proportions of leukocytes in lavage fluid were similar between groups.

Conclusions:

• Pretreatment with aerosolized Red#3+PG increases airway leukocyte concentration in broilers.
• Elevated airway leukocytes are a potential contributing factor to the enhanced pulmonary hypertension response to LPS.