Effects of platelet activating factor on the distribution of radiolabelled leucocytes and platelets in normal horses and asymptomatic horses with chronic obstructive pulmonary disease.
Abstract: Antigen challenge is known to cause the recruitment of neutrophils to the lungs of horses with chronic obstructive pulmonary disease (COPD). To evaluate a possible role of platelet activating factor (PAF) in this process, the effects of PAF on the distribution of radiolabelled neutrophils were compared in normal horses and asymptomatic horses with COPD. Changes in lung function, heart rate and the distribution of platelets and eosinophils were also measured. PAF (5 ng kg-1 intravenously) caused immediate but transient increases in the number of radiolabelled neutrophils in the lungs and a concomitant decrease in the peripheral neutrophil count. The total numbers of circulating leucocytes and neutrophils were also significantly decreased by PAF. Rapid and reversible increases in heart rate, respiratory rate and pleural pressure were also observed. In separate experiments, the numbers of radiolabelled eosinophils and platelets in the lungs increased transiently after the administration of PAF. The responses to PAF were qualitatively and quantitatively similar in normal horses and asymptomatic COPD horses. The PAF receptor antagonist WEB2086 (3 mg kg-1 intravenously) inhibited the effects of PAF. These results suggest that PAF, if released in the lungs of horses with COPD during an antigen challenge, might contribute to the recruitment of leucocytes and the respiratory changes.
Publication Date: 1996-09-01 PubMed ID: 8880978DOI: 10.1016/s0034-5288(96)90083-1Google Scholar: Lookup
The Equine Research Bank provides access to a large database of publicly available scientific literature. Inclusion in the Research Bank does not imply endorsement of study methods or findings by Mad Barn.
- Journal Article
- Research Support
- Non-U.S. Gov't
Summary
This research summary has been generated with artificial intelligence and may contain errors and omissions. Refer to the original study to confirm details provided. Submit correction.
This research investigates whether the platelet activating factor (PAF) plays a role in the migration of neutrophils to the lungs in horses with chronic obstructive pulmonary disease (COPD). Tests were performed on both normal horses and horses with asymptomatic COPD, considering effects on lung function, heart rate, and blood cell distribution.
Objective and Method
- The research’s main objective was to determine the role of PAF in the movement of neutrophils to the lungs in horses suffering from COPD. This was done by comparing the effects of PAF on radiolabelled neutrophil distribution in normal horses and horses suffering from asymptomatic COPD.
- PAF was administered to the horses intravenously, and changes in the distribution of neutrophils, other leucocytes, platelets, and eosinophils were observed. Also, lung function and heart rate changes were taken into account.
Key Findings
- The administration of PAF led to immediate but transient increases in the quantity of radiolabelled neutrophils in the lungs of the horses, accompanied by a decrease in peripheral neutrophil count.
- The total number of circulating leucocytes and neutrophils also significantly decreased as a result of PAF administration.
- The administration of PAF led to quick and reversible increases in horse heart rate, respiratory rate and pleural pressure.
- In separate experiments, numbers of radiolabelled eosinophils and platelets in the lungs increased briefly post-PAF administration.
- These responses were observed in both normal and asymptomatic COPD horses, indicating a similar reaction to PAF.
Implications
- The consistent responses in both normal horses and horses with asymptomatic COPD to PAF suggest that PAF plays a major role in recruiting leucocytes, which could lead to respiratory changes in horses challenged by antigens.
- The PAF receptor antagonist WEB2086 showed its potential in inhibiting the effects of PAF, thus, it could be explored as a target for therapeutic intervention in COPD horses.
Cite This Article
APA
Fairbairn SM, Marr KA, Lees P, Cunningham FM, Page CP.
(1996).
Effects of platelet activating factor on the distribution of radiolabelled leucocytes and platelets in normal horses and asymptomatic horses with chronic obstructive pulmonary disease.
Res Vet Sci, 61(2), 107-113.
https://doi.org/10.1016/s0034-5288(96)90083-1 Publication
Researcher Affiliations
- Department of Veterinary Basic Sciences, Royal Veterinary College, North Mymms, Hatfield, Hertfordshire.
MeSH Terms
- Analysis of Variance
- Animals
- Azepines / pharmacology
- Blood Platelets / drug effects
- Blood Platelets / physiology
- Eosinophils / drug effects
- Eosinophils / physiology
- Heart Rate / drug effects
- Horse Diseases
- Horses
- Indium Radioisotopes
- Leukocyte Count
- Lung Diseases, Obstructive / blood
- Lung Diseases, Obstructive / physiopathology
- Lung Diseases, Obstructive / veterinary
- Neutrophils / drug effects
- Neutrophils / physiology
- Platelet Activating Factor / pharmacology
- Platelet Aggregation Inhibitors / pharmacology
- Pleura
- Pressure
- Reference Values
- Respiration / drug effects
- Respiratory Function Tests / veterinary
- Time Factors
- Triazoles / pharmacology
Citations
This article has been cited 2 times.- Miglio A, Falcinelli E, Mezzasoma AM, Cappelli K, Mecocci S, Gresele P, Antognoni MT. Effect of First Long-Term Training on Whole Blood Count and Blood Clotting Parameters in Thoroughbreds. Animals (Basel) 2021 Feb 9;11(2).
- da Silva MB, Dessy C, Coghe J, David JL, Lekeux P. Protective effects of WEB 2086 (PAF antagonist) and ketoprofen (NSAID) on PAF-induced changes in the morphological ultrastructure of blood platelets in calves. Vet Res Commun 1998 Jun;22(4):273-91.
Use Nutrition Calculator
Check if your horse's diet meets their nutrition requirements with our easy-to-use tool Check your horse's diet with our easy-to-use tool
Talk to a Nutritionist
Discuss your horse's feeding plan with our experts over a free phone consultation Discuss your horse's diet over a phone consultation
Submit Diet Evaluation
Get a customized feeding plan for your horse formulated by our equine nutritionists Get a custom feeding plan formulated by our nutritionists
