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  • Author or Editor: Toyohiko Yoshihara x
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Abstract

Objective

To characterize surfactant protein isolated from bronchoalveolar lavage fluids of healthy horses.

Animals

10 Thoroughbreds (5 males, 5 females; 26 to 40 months old) that did not have a history or clinical signs of respiratory tract disease.

Procedure

Bronchoalveolar lavage fluid (BALF) was obtained and centrifuged at 33,000 × g. Lipid was removed from precipitated fractions by means of extraction with 1-butanol, and organic solvent-insoluble protein precipitates were dialyzed against Tris buffer. The suspension was centrifuged, and supernatant was placed in a mannose-Sepharose affinity column, with calcium. The bound protein fraction was analyzed by means of sodium dodecyl sulfate-polyacrylamide gel electrophoresis, western immunoblot analysis, and amino acid sequencing. A liposome-aggregation assay was also performed, using purified proteins.

Results

Protein isolated by use of mannose-affinity matrices was identified as surfactant protein A (SP-A). It had carbohydrate-binding and phospholipid-aggregation properties characteristic of SP-A isolated from other animal species. The partial primary sequence of the isolated protein had high homology with rat and human SP-A. Furthermore, the equine SP-A reacted with anti-human and anti-rat SP-A specific antibodies.

Conclusion

Analysis of these findings indicated the existence of SP-A in pulmonary tissues of horses.

Clinical Relevance

Measurement of SP-A concentrations may be useful for clinicians evaluating pulmonary disease of horses. (Am J Vet Res 1999;60: 169-173)

Free access
in American Journal of Veterinary Research

Abstract

Objective

To characterize surfactant protein D (SP-D) isolated from bronchoalveolar lavage fluid (BALF) of healthy horses.

Sample Population

BALF from 10 Thoroughbreds (5 males, 5 females; 26 to 40 months old) without history or clinical signs of respiratory tract disease.

Procedure

BALF was obtained and centrifuged at 33,000 × g. The supernatant was applied to a mannose-Sepharose 6B affinity column in the presence of calcium, and the bound protein fraction was analyzed by use of sodium dodecyl sulfate-polyacrylamide gel electrophoresis, immunoblot analysis; amino acid composition was determined and partial sequencing was done. Phospholipid binding and liposome aggregation assay were performed, using purified proteins.

Results

The protein isolated by use of mannose affinity matrices was SP-D. It bound carbohydrates and phosphatidylinositol, which are the characteristic features of SP-D isolated from other animal species. Amino acid analysis and partial primary sequence of the isolated protein indicated high homology with rat and human SP-D. Furthermore, immunoblot analysis indicated that equine SP-D reacted with human and rat SP-D-specific antibodies.

Conclusion and Clinical Relevance

SP-D exists in equine lungs; its measurement may be useful in evaluating equine lung disease. (Am J Vet Res 1999;60:368–372)

Free access
in American Journal of Veterinary Research

Abstract

Objective

To study the effects of extended transportation on the composition of bronchoalveolar lavage fluid (BALF) obtained from horses.

Animals

30 horses (14 males, 16 females; 25 Thoroughbreds and 5 Thoroughbred-Arabian crossbreds; 27 to 30 months old) without a history or clinical signs of respiratory tract disease. Bronchoalveolar lavage was performed on nontransported control horses (groups 1 and 2) and transported horses (group 3).

Procedure

20 horses were used to determine the effect of 41 hours of transportation on the composition of BALF (group 3). Bronchoalveolar lavage fluid was analyzed for recovered volume, number and distribution of nucleated cells, total protein and phospholipid concentrations, and phospholipid composition.

Results

Total number of nucleated cells in BALF from group-3 horses increased by approximately fourfold after transportation. Total protein concentration in BALF from group-3 horses also increased by approximately fivefold after transportation. Total phosphorus concentrations in group-3 horses decreased significantly from time 0 to immediately after transportation. In group-3 horses, the most characteristic change in composition of BALF after transport was a significant decrease in the concentration of phosphatidylglycerol.

Conclusion and Clinical Relevance

The decrease in phosphatidylglycerol concentration in BALF after transportation indicates a reduction in the quantity of surfactant. This change may reflect either a decreased production of surfactant by alveolar type II epithelial cells or an increased removal of surfactant from the alveolar region. It is likely that extended transportation resulted in a decreased concentration of surfactant in BALF. Such a decrease may reduce the pulmonary defence mechanisms in the alveolar region, possibly resulting in infection. (Am J Vet Res 1997;58:531–534)

Free access
in American Journal of Veterinary Research