Invasive Hemodynamic Monitoring in Hamsters

Studies were performed in male Golden Syrian hamsters (80–90 g, Charles River Laboratories, Boston, MA, United States). The experimental protocol is similar to that reported in a previous study by our group (Ao-Ieong et al., 2017 (link)). Animals were initially anesthetized using sodium pentobarbital (40 mg/kg IP). Subsequently, the animals were implanted with left jugular vein and left femoral artery catheters. A LV conductance catheter was introduced through the right carotid artery. A tracheotomy was performed (polyethylene-90 tube), and animals were ventilated (TOPO ventilator, Kent Scientific, Torrington, CT, United States) at a respiration rate of 90 breaths/min and peak inspiratory pressure of 20 cmH₂O to aid with breathing in the supine position. Animals were placed on a heating pad to maintain core body temperature at 37 °C and after instrumentation, volatile anesthesia (0.6%/vol Isoflurane, Drägerwerk AG, Lübeck, Germany) was administered using a vaporizer connected to the ventilator to preserve the depth of anesthesia during the experimental protocol. Depth of anesthesia was continually verified via toe pinch, and, if needed, isoflurane concentration was increased by 0.1%/vol to prevent animal discomfort. Experimental setup is presented in Figure 1C.