Thermalert th 8

(+)-Methamphetamine hydrochloride (METH) (Sigma-Aldrich, St. Louis, MO, USA) or saline was administered to rats in a binge (10 mg/kg, every 2 h in four successive intraperitoneal (i.p.) injections) or chronically (20 mg/kg, daily, for 10 days, i.p.). Both paradigms are established as models of METH neurotoxicity in rats and other experimental animals. METH neurotoxicity (neurodegeneration or damage to neuronal components within neuronal terminals or cell bodies causing dysregulation of neuronal function) is associated with hyperthermia [33 (link)], which peaks at approximately at 1 h after i.p. injection of METH. Therefore, core body temperatures were measured via a rectal probe (Thermalert TH-8; Physitemp Instruments, Clifton, NJ, USA) before the treatments (baseline temperatures) and 1 h after each METH or saline injection. Rats were sacrificed by decapitation at 1 h, 24 h or 7 days after the last injection of the drug or saline. For some analyses, rats were sacrificed 24 h after the first two days of chronic METH administration, at which point the rats were injected with the same total dose of METH as the binge METH rats (2 × 20 mg/kg and 4 × 10 mg/kg, respectively). The experimental design is shown in Figure 1.

(+)-Methamphetamine hydrochloride (METH, 10 mg/kg) (Sigma-Aldrich, St. Louis, MO) or saline (1 mL/kg) was administered to the rats every 2 h in four successive intraperitoneal (i.p.) injections. METH neurotoxicity is associated with hyperthermia, which peaks at approximately 1 h after each injection. Therefore, the core body temperatures of the rats were measured with a rectal probe digital thermometer (Thermalert TH-8; Physitemp Instruments, Clifton, NJ) before the beginning of the treatment (baseline temperatures) and at 1 h after each METH or saline injection. Rats were sacrificed by decapitation at 1 h (used for LINE-1 methylation analysis), 24 h or 7 days (used for multiple analysis) after the last injection of the drug or saline.

Four-week-old piglets (male n = 5, female n = 5; body weight: 10.4 ± 0.2 kg) were involved in our study. The animals were premedicated by the intramuscular administration of azaperone (8 mg/kg), midazolam (0.75 mg/kg) and atropine (25 μg/kg). Twenty minutes later, the animals received inhalation induction of anesthesia by sevoflurane (up to 6% end-tidal concentration) and an ear vein was cannulated (22G Abbocath, Abbott Medical, Baar/Zug, Switzerland). Animals then received fentanyl (2 μg/kg) and atracurium (0.5 mg/kg) before performing laryngoscopy and tracheal intubation with a 5.5 cuffed tube. Maintenance of anesthesia was achieved by i.v. infusion of propofol (10–15 mg⋅kg^–1⋅h^–1), fentanyl (10 μg⋅kg^–1⋅h^–1) and midazolam (0.1 mg⋅kg^–1⋅h^–1). After ensuring adequate levels of anesthesia and analgesia, atracurium was infused (1 mg⋅kg^–1⋅h^–1) to provide neuromuscular blockade. Piglets were mechanically ventilated in a supine position (Servo-I, Maquet Critical Care, Solna, Sweden) with PRVC mode (VT: 7 ml/kg, RR: 30–35/min, FiO₂: 0.4, PEEP: 5 cmH₂O). The femoral artery and jugular vein were cannulated for continuous hemodynamic measurements and blood withdrawal. The body temperature was measured by a rectal thermometer (Thermalert TH-8, Physitemp, Clifton, NJ, United States) and maintained at approximately 38°C using a heating pad (Miostar, Zurich, Switzerland).