The Experimental Study Between Ischemia Reperfusion And Apoptosis On Femoral Head Of Immature Rabbits

Objective: In this investigation we utilized to found the model of ischemia reperfusion injury on the femoral head of immature rabbits, to observe the influence of ischemia reperfusion injury on the femoral head of immature rabbits by light microscope, transmission electron microscope (TEM) , TUNEL means, to investigate the relations between ischemia reperfusion injury and apoptosis initially, which will be useful to explore the mechanism of degeneration of the femoral head suffered from the ischemia reperfusion injury and offer theoretical proofs to prevent femoral head necrosis after reposition.Methods: (1) According to the model of Yokota J, adopted block-open arteria iliaca communis to establish the model of ischemia reperfusion on femoral head of immature rabbits. 32 immature New Zealand white rabbits (including 2 rabbits were normal group) were grouped into 3 randomly, represently ischemia reperfusion 4, 8, 12h. Each group were subgrouped into 5 randomly, which represented ischemia group and reperfusion 4, 24, 72, 168h groups respectively. The left femoral head was experimental side. Separated arteria iliaca communis carefully, artery clamp blocked bloodstream below the crotch of both arteria iliaca communis, common iliac vein was not blocked. Observed the capillary filling of hindlimb far-end, recorded the time of ischemia and reperfusion. Executed animals to obtain specimens at time point respectively. (2) Made paraffin section, observed the pathohistology structure of specimen after ischemia and reperfusion by HE dyeing. (3) Observed the ultrastructure after ischemia and reperfusion under transmission electron microscope. (4) Utilized TUNEL technique toobserve histology change at molecular biology level.Results: (1) The time of capillary filling in the experimatal side of hindlimb was longer than that of opposite side and the temperature droped after blocked arteria iliaca communis; capillary filling time recovered and temperature returned gradually when opened arteria. (2) Morphosis of femoral head was normal basically, cellular damage showed nucleus swelled in ischemia reperfusion 4h group; in ischemia reperfusion 8h group, morphosis disordered partly, cellular damage showed karyopyknosis, osteocyte lacune deepened, a small quantity cytolysis and disappeared; in ischemia reperfusion 12h group, morphosis disordered, cellular damage showed karyopyknosis, osteocyte lacune deepened, a small quantity cytolysis and disappeared. (3) Ultrastructure under TEM showed cell shrinked, surface projection disappeared, nucleus pyknosis lightly, caryotheca introcessed caryotin unevenness in ischemia 8h group; in reperfusion 72h group, cell shrinked, lacune deepened, nucleus pyknosis, caryotin thickness, enriched under caryotheca , like lump, circularity or crescent; in reperfusion 168h group cell shrinked, lacune deepened, caryotheca integrity or excalation, caryotin thickness , enriched under caryotheca , like horoscope, circularity or crescent. (4) The positived dyeing cells showed buffy color under TUNEL dyeing, the signal distributed in intranuclear, bouncary distinct and the size verily, no inflammation surrounded. endochylema stained partly. A small quantity positived dyeing cells in ischemia groups, between the reperfusion groups and contrast groups, the apoptosis rate p<0.05. In a specified time, the longer time of ischemia, the more positived dyeing cells. Under the same ischemia time, followed the time extension of ischemia reperfusion, more positived dyeing cells appeared, the apoptosis rate showed ascending tendency gradually.Conclusions: (1) Adopted block-open arteria iliaca communis to establish the model of ischemia reperfusion on femoral head of immature...