Embolic pneumopathy induced by oleic acid. A systematic morphologic study

Area of Science:

• Pulmonary Pathology
• Animal Models
• Fibrosis Research

Background:

• Acute and chronic pulmonary lesions can result from oleic acid exposure.
• Developing reliable models for lung fibrosis is crucial for research.

Purpose of the Study:

• To systematically study acute and chronic pulmonary lesions induced by oleic acid.
• To propose and validate a new model for pulmonary interstitial fibrosis using oleic acid injections.

Main Methods:

• Intravenous injections of oleic acid (0.045 or 0.09 g/kg) in adult dogs.
• Morphological studies using light and electron microscopy and morphometry at various time points (hours to weeks).
• Repeated weekly injections (0.09 g/kg) over 1-3 months to induce chronic fibrosis.

Main Results:

• Early stages showed thrombosis and necrosis, followed by repair with Type 2 cell proliferation.
• Lipid-laden macrophages were observed, indicating metabolic processes.
• Pulmonary interstitial fibrosis was consistently observed in the late stages, with lesion extent correlating to injection frequency.

Conclusions:

• The proposed model of pulmonary interstitial fibrosis using repeated oleic acid injections is effective and reproducible.
• The model is suitable for both pathologists and physiologists due to consistent fibrosis induction and low mortality.
• This study provides insights into the stages of oleic acid-induced lung injury and repair.