The Dacron grafts seeded with autologous venous fragments were implanted into IVC of 13 canines as seeded group and the control grafts (8 cases), which were only preclotted with fresh blood. The amounts of cAMP and cGMP in serum and within platelet were measured. All of the specimens explanted at exsaguination were observed morphologically. The results shown that the total patency rate were 61.5% in seeded group, but 25.0% in control one and new endothelial lining formed at two weeks after implantation of the seeded grafts. The amounts of cAMP in serum and within platelet were higher in seeded group, but the amounts of cGMP were lower in serum and within platelet. These were in accordance with the results that the endothelialization of the grafts were complete in seeded group but not complete in control one. The results indicate that seeding Dacron with autologous venous fragment makes new endothelium formed at two weeks after implantation, increases the amounts of cAMP in serum and within platelet, but reduces the amounts of cGMP and thus improves graft patency rate.
【Abstract】ObjectiveTo investigate the effects of endogenous photodynamic therapy (PDT) on intracellular cAMP and cGMP concentrations of human colon carcinoma cell lines SW480. MethodsSW480 cells were divided into control group, light group, δaminolevulinic acid （ALA） group (ALA group) and endogenous PDT group (ALAPDT group). Intracellular cAMP and cGMP concentrations of each group were detected by radioimmunoassay at 30, 60, 90 and 120 min after irradiation. ResultsThere was a significant increase in intracellular cAMP concentration of ALAPDT group at 30 min after irradiation (P＜0.001) and sequent decrease, but intracellular cAMP concentrations of ALAPDT group at 60, 90 and 120 min after irradiation had no statistical difference than the other groups (Pgt;0.05). Intracellular cGMP concentration of different time point of each group was not significantly different. ConclusionThese results indicate that the cytoprotection of SW480 cell are produced by an instantaneous increase in the intracellular cAMP concentration while endogenous PDT is killing SW480 cell.