Interference of bronchographic agents with lung surfactant

Area of Science:

• Pulmonary Physiology
• Pharmacology
• Histopathology

Background:

• Bronchography is a medical imaging technique used to visualize the bronchial tree.
• Contrast agents are essential for effective bronchography, but their potential effects on lung physiology require investigation.
• Understanding the impact of contrast agents on lung mechanics and surfactant function is crucial for patient safety.

Purpose of the Study:

• To evaluate the effects of Dionosil Oily, a propyliodone-based contrast agent, on the pressure-volume characteristics and stability of rabbit lungs.
• To investigate the influence of peanut oil and tantalum powder, components of the contrast agent, on lung function.
• To assess the impact of these agents on lung surfactant activity in vitro and in situ.

Main Methods:

• Rabbit lungs were instilled with Dionosil Oily (propyliodone in peanut oil) or tantalum powder in the right bronchi, with left lungs serving as controls.
• Pressure-volume curves of excised lungs were analyzed to determine compliance and stability index.
• Histological examination was performed to identify any tissue-level changes.
• Surface balance experiments were conducted using lung surfactant and dipalmitoyl phosphatidylcholine (DPPC) with the contrast agent components.

Main Results:

• Dionosil Oily and peanut oil significantly reduced lung compliance and stability, indicated by lower air retention during deflation.
• Histology revealed microatelectasis associated with propyliodone crystals and peanut oil.
• Tantalum powder did not significantly alter lung function or histology.
• Surface balance studies showed increased minimum surface tension with propyliodone, peanut oil, and particles, suggesting reduced surfactant activity.

Conclusions:

• The oil suspension of propyliodone (Dionosil Oily) impairs lung mechanics, likely by reducing surfactant activity in the lungs.
• Peanut oil and propyliodone particles may contribute to reduced lung surfactant function and increased minimum surface tension.
• Tantalum powder appears to be a physiologically inert component in this context.