Effects Of Recombinant Human Growth Hormone On Endothelialization Of Vascular Prosthesis

Objective To investigate the effects of recombinant human growth hormone on endothelialization of vascular prosthesis after dogs' abdominal aorta replaced by expended polytetrafluoroethylene vascular and treatment with recombinant human Growth Hormone (rhGH).Methods Twenty-eight 12-month-old mongrel dogs in Beijing area were divided randomly into the group experiment (group E, n=14) and the group contrast (group C, n=14). All animal's abdominal aorta were replaced with the expanded polytetrafluoroethylene(e-PTFE). The dogs in group E were hypodermicly injected with rhGH (0.1IU/kg/d) at 16:30 in every day for 14 days. The rhGH was not use for dogs in group C, and other treatments were same as those in group E. The dogs were executed 1 month (n=2), 2 months (n=6), and 3 months (n=6) after operation respectively. Then we observed the change of tunica intima vasorum ultramicrostructure of grafts and determined the thickness of artificial tunica intima vasorum and accounted endothelial cells by means of HE staining, light microscope, transmission electron microscope and scanning electron microscope respectively.Results:â‘ 1 months after operation: fibrous membrane covers on internal surface of grafts in all samples in two groups at 1 month after operation, where we can find small amounts of spindle cells. But the intima formation of vascular prosthesis in group E is more consummate than that in group C.â‘¡2 months after operation: There is a completed endothelial layer covered the entire internal surface of grafts in group E. The endothelial cells are matured and conjunct tightly. But the endothelial cells in group C are distributed irregulatedly and conjunct untightly. Few foot processes of endothelial cells can be observed, periplast is dropsy, caryoplasm is scattered. There is a lot of fibroplasia on internal surface of grafts in contrast's group.â‘¢3 months after operation: There are a litter fibrocytes and smooth muscle cells under endothelium in group E. Endomembrane of grafts in group C are obviously thickening, thrombocytes and fibrocytes cover the internal surface of grafts like fluffed cotton.â‘£Computer image analysis results: the thickness of intima in group E either at 2 months or at 3 months after operation, are obviously thinner than those in group C (P<0.01) . The number of endothelial cells in group E is more than that in group C at 2 months after operation (P<0.01) . There is no significant difference between group E and group C on endothelial cell counting at 3 months after operation.Conclusion Administration of rhGH may improve endothelial cell multiplication and maturity, and inhibit the endomembrane to hyperplasy.