GUILLOTINE RAPID FREEZE-CLAMPING OF EXPERIMENTAL ANIMALS.

A mechanical device is developed which enables the cross-sectioning and freeze-clamping of a target organ in 120 msec in an experimental animal. Because metabolism and flow are rapidly fixed in situ, two dimensional display of metabolism will be possible with biochemical and histochemical techniques. The device consists of: 1) cross-sectioning 2) transfering the sample to the freezing system 3) freezing. In order to prove the usefulness of the device, beating hearts of 7 open chest dogs were cut along the short-axis plane in 4mm width and freeze-clamped to 2. 5 mm width. Anatomical structure and metabolic state (energy charge and NADH fluorescence) of the samples were well preserved. In conclusion, this method gives an adequate simulation model in analyzing the results of three dimensional display of metabolism by PET or NMR methods.