A method for bronchoalveolar lavage in live pigs

Abstract

SUMMARY In order to isolate porcine alveolar macrophages and to quantitatively study the components of recovered lung fluid, a bronchoalveolar lavage technique in living pigs was developed. Lung lavage was performed after introducing a catheter through the mouth via the trachea in the diaphragmatical lobe. Thirty ml of phosphate-buffered saline (PBS) was introduced into the lung and the fluid was aspirated after one minute. Following this, another 15 ml of PBS was introduced into the lung and aspirated after one minute. The recovered volume of the second lavage averaged 15 ml (± 0.4 S.E.M.). Cells thus obtained from specificpathogen-free (SPF) pigs were composed of 98% macrophages. Lavage fluids from conventionally bred pigs contained 67% macrophages, 17% neutrophilic granulocytes and about 16% lymphocytes, demonstrated by their morphology and acid phosphatase activity. The viability of the recovered cells was over 98% in both SPF and conventionally bred pigs.The dilution of the aspirated lung liquid was determined by using methylene blue in the introduced fluid. The calculated dilution factor of the recovered lavage fluid was 0.58 (S.E.M. 0.02).No influence was noticed on the number or composition of cells nor on the dilution factor when lung lavage was done in SPF pigs twice a week during a four week period.The protein concentration in lavage fluid from SPF pigs was 142 (SD ± 26) mcg/ml. In conventionally bred pigs, however, a wide variation (276 ± 229 mcg/ml) in protein content was noted. Lavage fluid supernatant of some animals had a bactericidal effect on Haemophilus Pleuropneumoniae strain 13261, whereas no bactericidal effect was noted in other lavage samples.

Bronchoalveolar Lavage Cytology and Hematology: A Comparison between High and Low Health Status Pigs at Three Different Ages

“…The findings in the low health status pigs are in agreement with those of others who have reported that conventionally raised pigs have a lower percentage of AMs and higher percentages of lymphocytes and neutrophils in BAL fluid than specific-pathogen-free or germ-free pigs. 8,24 Conventionally raised pigs are exposed to a variety of antigenic stimuli, including pathogenic microorganisms, which are responsible for the increased percentages of neutrophils and lymphocytes. 1,9,18,20 In contrast with BAL data, hematology results of the high health status pigs were not influenced much by age and were similar to previously reported values.…”

“…This is in agreement with findings by others. 4,18,24 A third BAL was done at necropsy after removing the lung from the chest cavity. The BALs were done at 2.5-week intervals, which would allow enough time for resolution of any mild inflammatory response.…”

“…2,4,8,13,18,20,24 Recently, researchers have reported that when comparing virus isolation from serum or AMs at selected time points after exposure to PRRSV, AMs were the most consistent PRRSV-positive sample. 13 These findings suggest a diagnostic purpose of BAL in pigs.…”

Branched-Chain Amino Acids Are Required for the Survival and Virulence ofActinobacillus pleuropneumoniaein Swine

“…Bronchoalveolar lavage fluid (BALF) was collected from five healthy 12-to 14-week-old Yorkshire-Landrace pigs by using standard veterinary procedures (52). All animal use protocols were approved by the Michigan State University Institutional Animal Care and Use Committee.…”

“…The volume of pulmonary epithelial lining fluid (ELF) in the recovered BALF was calculated both by measurement of the concentration of methylene blue in the BALF (3,52) and by using urea as a marker of dilution (39). Concentration of free amino acids and of urea in the BALF were measured by physiological amino acid analysis on a Hitachi I-8800 amino acid analyzer (Hitachi High Technologies America, Pleasanton, CA) (45) at the Michigan State University Macromolecular Structure Facility and compared to the concentration of urea in a plasma sample collected immediately prior to the lavage procedure.…”