The hydrophilic proteins of lung surfactant as a prognostic marker in experimental pneumonia

Abstract BACKGROUND: SP-A and SP-D are hydrophilic proteins which regulate the inflammatory response of the lung. Pasteurella multocida is one of the most common bacteria isolated from calves suffering from shipping fever pneumonia, one of the most problems in dairy herds. OBJECTIVE: Evaluation of surfactant content may provide a valuable diagnostic tool for detection of calf pneumonia due to Pasteurella multocida and also state of treatment. METHODS: Ten Holstein-Frisian bull calves aged 4 months with body weight of 120 ± 5 kg were selected for study in two groups. The Pasteurella multocida (PMC66 Razi) was used in the present study for inducing pneumonia. The Bronchoalveolar lavage (BAL) process was done in selected calves. BAL fluid was collected and centrifuged and finally the sediment (crude surfactant) was reserved at -20˚C.The cytological evaluation and surfactant content was assayed by ELISA, TPL kit assay and HPLC. RESULTS: The serum levels of SP-A and SP-D in pneumonic group were significantly elevated. Although the increased Bronchoalveolar lavage fluid (BALF) level of SP-A in pneumonic cases was found as compared with the control animals, but the statistical analysis didn't show any significant differences between two groups. The level of SP-D in BALF of pneumonic group significantly elevated. The amount of Dipalmitoylphosphatidylcholine (DPPC) in pneumonic group decreased significantly in comparison control group. CONCLUSION: Pasteurella inducing pulmonary can changed the major component of lung surfactant which evaluation of these markers can be helpful as an appropriate tool in diagnostic state of pneumonia and healing.