2020 Volume 61 Issue 1 Pages 11-17
Objectives: Contrast agent (CA) aspiration is an established complication of upper gastrointestinal and videofluoroscopic swallow studies. The underlying molecular biological mechanisms of acute response to CA aspiration in the respiratory organs remain unclear. The aims of this study were to elucidate the histological and biological influences of three kinds of CA on the lung and to clarify the differences between acute and chronic responses.
Methods: Eight-week-old male Sprague Dawley rats were divided into 5 groups (n=6 per group). Three groups underwent tracheal instillation of one of three CAs: barium sulfate (Ba), ionic iodinated contrast agent (ICA), and non-ionic iodinated contrast agent (NICA). Sham and control groups were instilled with air and saline. Animals were euthanized 2 days (acute response) and 30 days (chronic response) after treatment, and histological and gene analyses were performed.
Results: No animal died after CA or sham/control aspiration. Ba caused severe prominent inflammatory cell infiltration on day 2 and remaining Ba particles caused histopathologic changes and inflammation in the lung on day 30. Iodinated ICA and NICA did not result in perceptible histologic change. Increases in expressions of inflammatory cytokines were observed in Ba aspiration rats on day 2 (Tnf, Il1b, Ifng) and day 30 (Tnf). Other inflammatory cytokines and fibrosis-related genes did not alter between groups.
Conclusion: Barium caused significantly more acute and chronic lung inflammation in a rodent model than ionic and non-ionic iodinated contrast agents. Our study highlights the importance of considering pulmonary inflammation after barium aspiration.
