Azaperone

All experiments were performed in accordance with the German legislation governing animal studies. Official permission was granted from the governmental animal care office (Landesamt für Natur, Umwelt und Verbraucherschutz Nordrhein-Westfalen, Recklinghausen, Germany). Female German landrace pigs from a disease-free barrier breeding facility were housed in ventilated rooms and allowed to acclimatize to their surroundings for a minimum of 5 days before surgery. The animals, weighing around 60 kg, were fasted 12 hrs prior to the experiments. For premedication, the animals received an intramuscular injection of 4 mg kg⁻¹ azaperone (Stresnil, Janssen, Germany). Anesthesia was induced by intravenous injection of 3 mg kg⁻¹ propofol followed by oral intubation. The animals were ventilated with 40% oxygen at 20–26 bpm and a tidal volume of 10 mL kg⁻¹ to keep the end tidal partial carbon dioxide tension (pCO2) between 36 and 42 mmHg. Anesthesia was maintained with isoflurane at a concentration of 1%–1.5% (Forane, Abbott, Germany) and fentanyl (fentanyl, Janssen, Germany) at a concentration of 3-4 mg kg⁻¹. To compensate for basic fluid requirements volume, animals received Ringer's lactate (RL) solution at a rate of 4 mL kg⁻¹; after laparotomy, the constant infusion rate was set to 8 ml kg⁻¹ and not changed until infliction of trauma.

Female German Landrace pigs with 55,2 ± 1,9 kg body weight (BW, mean ± SEM) from a disease-free barrier breeding facility were housed in fully air-conditioned rooms (22 °C room temperature, 50% relative humidity) and allowed to acclimatize to their surroundings for a minimum of seven days and fasted for 12 h before surgery with free access to water. The animals were premedicated with 8 mg/kg BW azaperone (Stresnil, Janssen-Cilag GmbH, Neuss, Germany), 15 mg/kg BW ketamine (Ceva GmbH, Duesseldorf, Germany) and 10 mg atropine (1 ml/1% atropine sulfate, Dr. Franz Köhler Chemie GmbH, Bensheim, Germany) administrated intramuscularly. After cannulation of the femoral vein, 600 mL of venous blood for the ex vivo perfusion of the kidneys was withdrawn into sterile blood bags filled with 5,000 IU of heparin each (B. Braun Melsungen AG, Melsungen, Germany). The animals were thereafter euthanized by an IV administration of 1 mL/kg BW pentobarbital (Narcoren, Merial GmbH, Hallbergmoss, Germany). After cardiac arrest, a midline laparotomy was performed and both kidneys were explanted simultaneously to achieve an equal warm ischemic time. The duration from cardiac arrest until explantation was recorded and regarded as warm ischemic time. In compliance with the 3R principle, other organs of the animals were retrieved for different in-house research purposes.