Reversible pulmonary changes in rats dosed intravenously with imidazoles

Area of Science:

• Toxicology
• Pharmacology
• Pulmonary Medicine

Background:

• Chemical compounds St 91-Cl and St 600-Cl were investigated for potential toxic effects.
• Understanding the pulmonary toxicity of novel chemical entities is crucial for safety assessment.

Purpose of the Study:

• To evaluate the pulmonary toxicity of St 91-Cl and St 600-Cl following intravenous and oral administration in Sprague-Dawley rats.
• To determine dose-dependent effects and reversibility of observed pulmonary changes.

Main Methods:

• Acute intravenous toxicity studies with varying doses of St 91-Cl and St 600-Cl around the LD50.
• Subacute oral toxicity studies involving daily dosing for 4 weeks at different concentrations.
• Histopathological examination of pulmonary tissues to identify changes.

Main Results:

• Intravenous administration of higher doses of St 91-Cl and St 600-Cl induced acute pulmonary congestion, edema, and bleeding.
• These acute effects were followed by hemosiderosis in alveolar macrophages.
• All observed acute pulmonary changes were reversible.
• No pulmonary alterations were noted in subacute oral toxicity studies.

Conclusions:

• Intravenous St 91-Cl and St 600-Cl exhibit acute, reversible pulmonary toxicity in rats at higher doses.
• Oral administration in subacute studies did not result in pulmonary toxicity, suggesting a safer route of administration.