The experiments were performed in 56 newly weaned A/J male mice. Animals were maintained on a standard (C, 22% protein, 73% carbohydrate,

5% fat) or high-fat diet (OB, 12% protein, 52% carbohydrate, 36% fat). They received water ad libitum and were housed in micro-isolator cages (1/cage) with temperature control and a 12 h light:dark cycle. During 12 weeks, the body weight and food consumption of all mice were measured. The animals were further randomized to be sensitized and challenged with sterile ovalbumin (Albumin from chicken egg white – A5503, Sigma–Aldrich®, St. Louis, MO, USA) or saline. In the chronic allergic asthma groups, mice were immunized by intraperitoneal injection of 10 μg sterile ovalbumin (OVA) BMN 673 concentration in 0.1 ml saline on each of seven alternate days. Forty days after the beginning of sensitization, intratracheal challenge was performed with the following protocol: mice were treated with sevoflurane anesthesia. A 0.5-cm-long midline cervical incision was made to expose the trachea, and 20 μg OVA in 20 μl warm (37 °C) sterile saline (0.9% NaCl) were instilled. The cervical incision was closed with 5.0 silk suture and the mice were returned to their cage. The animals recovered rapidly after surgery. This procedure was performed three times, with a 3-day interval between instillations. No adjuvants were used in

check details the present protocol (Xisto et al., 2005). The control group (SAL) received saline instead of ovalbumin during both sensitization and challenge. Ventilatory variables and lung histology were analyzed in 28 mice (n = 7/group) while airway hyperresponsiveness, dynamic compliance,

and the inflammatory process in bronchoalveolar lavage fluid (BALF) were evaluated in a second group of 28 animals (n = 7/group). The mice were anesthetized Loperamide and euthanized by sectioning abdominal aorta and vena cava, yielding a massive hemorrhage that quickly killed the animals. Visceral adipose tissues were dissected from each animal according to defined anatomic landmarks, and weighed after mice were killed. Twenty-four hours after the last challenge, the animals were sedated (diazepam 1 mg ip), anaesthetized (thiopental sodium 20 mg/kg ip), and tracheotomized. A pneumotachograph (1.5 mm ID, length = 4.2 cm, distance between side ports = 2.1 cm) was connected to the tracheal cannula for the measurements of airflow. The pressure gradient across the pneumotachograph was determined by a differential pressure transducer (SCIREQ, SC-24, Montreal, Canada). Tidal volume was obtained by integration of the flow signal. During spontaneous breathing, durations of inspiration and expiration and the respiratory cycle time were measured from flow signal. Using these variables, we calculated respiratory frequency (f  ) and minute ventilation (V′EV′E).