Abstract:

BACKGROUND: It was very mature that protecting organs and tissues in liquid nitrogen at present, but the debates were different protective agents of that.
OBJECTIVE: To observe the effect of apoptosis and metabolization of trehalose as cryoprotectant for preserving aortic valve homograft in liquid nitrogen on their tissues and cells, and to seek the best protective agents and their optimal concentrations.  
METHODS: The aortas and pulmonary arteries obtained from New Zealand white rabbits and frozen in liquid nitrogen to 12, 15, 18 months, 0.1 mol/L dimethyl sulfoxide (DMSO), 0.1 mol/L trehalose, 0.1mol/L trehalose +0.1 mol/L DMSO, 0.2 mol/L trehalose+0.1 mol/L DMSO, 0.3 mol/L trehalose+ 0.1 mol/L DMSO was used in liquid nitrogen, respectively. After specimens rewarming, the apoptosis of the specimens was detected by immunohistochemistry method, and the metabolism of tissue cells was detected by glucose consumption.
RESULTS AND CONCLUSION: Immunohistochemistry and glucose consumption determination results showed that the freezing effects of 0.1mol/L trehalose + 0.1 mol/L DMSO and 0.2 mol/L trehalose+0.1 mol/L DMSO were the best. 0.3 mol/L trehalose+  0.1 mol/L DMSO, which was worse than 0.1 mol/L trehalose + 0.1 mol/L DMSO and 0.2 mol/L trehalose+0.1 mol/L DMSO, ranked above 0.1 mol/L trehalose. The worst was 0.1 mol/L DMSO. The trehalose as the cryoprotectant for preserving aortic valve homograft in liquid nitrogen had a good protective effect. The separate use of trehalose was better than the separate use of DMSO. The joint use of trehalose and DMSO was better than the separate use of either one. The best concentrations of trehalose of the joint use were between 0.1 mol/L and 0.2 mol/L.