|
Normal adult Korean dogs (Mongrel) were used for these experiments. Operations and cross circulations were performed under sterile conditions and anesthesia with intravenous sodium pentothal injection. Heparin was used as the anticoagulant before and during cross circulation. Two dogs were placed on operating tables so that their legs were together. The femoral arteries and veins in adjacent legs were isolated and cannulated with tubes of 1.0mm inside diameter. The arterial cannule of each animal was connected to the venous cannule of the other dog, and cross circulation was started and continued for 2 to 13 hours. This method is referred as direct cross circulation. A second method, indirect cross circulation, was devised to connect the arterial cannule of each dog to the venous cannule of the other dog through a glass bottle containing 20cc of ACD solution elevated one meter above the animals. With the venous tubing clamped, arterial blood flowed into the bottles. When 100cc of arterial blood had been collected, blood flow was reversed by clamping the arterial tubings and removing the venous clamps. The procedures were repeated for 5 hours. General condition, pulse, respiration, NPN. BUN and creatinine of blood content were observed and determined before, during and after cross circulation. The experiments were done in 7 pairs of animals by the direct method, and in 2 pairs by the indirect method. During the experiment, pulse and respiration became frequent and irregular. They showed sign of weakness. But dogs returned to normal in 1 to 3 days after the experiment. No significant differences were noted in the amount of blood NPN, BUN and creatinine content during and after cross circulation by both animals. However, the indirect method appears safer for the animals but less blood volume can be exchanged than in using the direct method.
|