Feasibility of Organ Transportation by a Drone: An Experimental Study Using a Rat Model.

BACKGROUND: Recently, the successful delivery of organs for transplantation using drones was reported. We investigated the influence of transportation by drones on the quality of liver grafts using a rat model. METHODS: Livers of 12 rats (8 and 32 weeks old) were divided into 2 groups of six. Livers were split into 2 parts and allocated to the drone or control groups (both n = 12). The drone experiment was conducted between islands in Nagasaki Prefecture, Japan. The distance between the islands was 12 km. Livers of the drone group were transported by a multicopter at a speed of 30 km-40 km/h over 60 m above sea level. Transported liver quality was analyzed by histology, and biochemistry data were compared between groups. RESULTS: Cold ischemia time did not differ between groups (902 min and 909 min, respectively). There were no differences in macroscopic findings regarding coloration and damage between groups. Aspartate aminotransferase (AST), alanine aminotransferase (ALT), and alkaline phosphatase (ALP) in preservation fluid were graft weight-corrected and compared, and no significant differences were found between groups: AST/g (4.61 vs 4.81 IU/L), ALT/g (2.78 vs 2.92 IU/L), and ALP/g (39.1 vs 37.0 IU/L). Immunochemical staining showed no significant difference between groups for terminal deoxynucleotidyl transferase dUTP nick and labeling staining (141 vs 113 cells), CD163 (818 vs 870 cells), and TNF-α (1.25 vs 1.41 scores). CONCLUSIONS: The simulation experiment of organ transport for transplantation by drones was successfully conducted. There were no differences in the quality of livers transported by drones or other means. Further studies including large-animal experiments could lead to future clinical applications.

Mibefradil reduces hepatic glucose output in HepG2 cells via Ca2+/calmodulin-dependent protein kinase II-dependent Akt/forkhead box O1signaling.

The effects and underlying mechanisms of mibefradil on gluconeogenesis and glycogenesis were investigated using insulin-resistant HepG2 human hepatocellular carcinoma cells and a mouse model of type 2 diabetes mellitus (T2DM). HepG2 cells were divided into one of four groups: control, palmitate (PA)-induced insulin-resistance (0.25 mM), low-concentration mibefradil (0.025 µM), or high-concentration mibefradil (0.05 µM). Glycogen synthesis and glucose consumption were evaluated in these HepG2 cells, and quantitative polymerase chain reaction (qPCR) and western blotting techniques were used to detect expression of forkhead box O1 (FoxO1), phosphoenolpyruvate carboxykinase (PEPCK), and glucose 6-phosphatase (G6Pase). Intracellular calcium concentrations were determined using Fluo-4 AM, and phosphorylation levels of calmodulin-dependent protein kinase II (CaMKII), protein kinase B (Akt) and FoxO1were detected by western blotting. Immunofluorescence was used for the localization and quantification of FoxO1.In vitro results were verified using a mouse model of T2DM. In HepG2 cells and mouse liver tissues, mibefradil decreased PA-induced cytoplasmic calcium levels and CaMKII phosphorylation, but increased the phosphorylation of Akt and FoxO1, thereby contributing to the cytoplasmic localization of FoxO1. Additionally, mibefradil alleviated PA-induced glucose output and insulin resistance through increased glucose consumption and glycogen synthesis, while decreasing the expression of key gluconeogenesis enzymes, including PEPCK and G6Pase. Mibefradil may help to control blood sugar levels by reducing glucose output and insulin resistance, and the mechanism of action may involve the Ca2+-CaMKII-dependent Akt/FoxO1 signaling pathway.