24ga catheter

To induce pulmonary fibrosis, 8–10-week-old C57BL/6J WT mice were anesthetized by i.p. injection of ketamine (75 mg kg⁻¹) and medetomidine (1 mg kg⁻¹). Animals were placed on a Tilting WorkStand for rodents (EMC Hallowell) and intubated intratracheally with a 24GA catheter (BD Biosciences) and delivered 30 μl bleomycin (1.5 U kg⁻¹ of body weight) (Sigma, 15361) or 30 μl aqueous iron solution containing a concentration of 8.3 mM Fe(II)sulfate and 8.3 mM Fe(III)nitrate (in total 16.5 mM iron); control animals received 30 μl PBS. Iron solution was sterile filtered with a 0.22-µm pore size syringe filter. Mice receiving intratracheal iron developed sepsis-like symptoms within a day, with severe weight-loss, from which they recovered on the fourth day post-iron. We found that treatment with a daily dose of subcutaneous buprenorphine (0.1 mg kg⁻¹) considerably mitigated these symptoms and the overall mortality in this model remained very low (<10%).

To induce pulmonary fibrosis, 8‐ to 10‐week‐old male C57BL/6 wild‐type mice were anesthetized by intraperitoneal injection with a mix containing ketamine (75 mg/kg) and medetomidine (1 mg/kg). The animals were placed on a Tilting WorkStand for rodents (EMC Hallowell) and intubated intratracheally with a 24GA catheter (BD Biosciences). Then, bleomycin (Sigma, #15361) was intratracheally inoculated in at 1.5 U/kg of body weight. Serial sections of the lung were stained with Sirius red to assess the presence of collagen. Whole slides were digitalized with a slide scanner (Mirax Scan, Zeiss) using polarized light, and images were acquired with the Pannoramic Viewer Software (3DHISTECH). Image analysis and quantification of colored signals (red, yellow, and green) within damaged areas was performed in a completely automated manner using the AxioVision software package (Zeiss). At least seven mice per group were quantified.

Mice were anesthetized by intraperitoneal injection with a mix containing ketamine (75 mg/kg) and medetomidine (1 mg/kg). Animals were placed on a Tilting WorkStand for rodents (EMC Hallowell) and intubated intratracheally with a 24GA catheter (BD Biosciences). Then, animals were placed in a plethysmograph adapted for anesthetized rodents (emka TECHNOLOGIES). A MiniVent Model 845 (Harvard Apparatus) connected to the plethysmograph was used to ventilate the mice at a frequency of 150 beats/min and 10 ml/kg of tidal volume. Transpulmonary pressure was measured with a pressure transducer connected to the cannula. Airflow and tidal volume were determined using a flow transducer fixed to the plethysmograph chamber. Lung resistance (L_R) and compliance dynamics (C_dyn) were calculated and analyzed with iox2 software (emka TECHNOLOGIES).