Objective To investigate the effect of constitutively active Akt1 gene on rat engrafted islets in apoptosis and revascularization, and to explore potential method of gene therapy in the islet transplantation. Methods Rat islet which was transfected constitutively actived Akt1 gene via adenovirus vector using MOI=500. Thirty-six streptozotocin induced diabetic Wistar rats were divided into 3 groups complete randomly: Adv-CA-Akt1 group, Adv-LacZ group and simple transplantation group. Blood glucose and insulin were determined after operation. TUNEL was used to detect the apoptotic islet cells. HE and immunohistochemical staining of insulin were used to evaluate the histology of the islet grafts. The microvessel density (MVD) was determined by CD31 immunohistochemical staining. Results The fasting glucose level in Adv-CA-Akt1 group restored to normal 2 days after transplantation. However, in Adv-LacZ group and simple transplantation group, it reduced but still kept being hyperglycemia. And the serum insulin level was higher than other two groups ( P ＜ 0.05). Compared to simple transplantation group and Adv-LacZ group, apoptotic rate decreased 25% in Adv-CA-Akt1 group, a large number of islet grafts were seen under the capsule of the kidney, which were positively stained by insulin antibody. In the other two groups, the islet groups mass were lighter, and few positively stained by insulin antibody. MVD showed lighter positive endothelial cells stained by CD31 antibody in the other two groups than Adv-CA-Akt1 group ( P ＜ 0.05). Conclusion Constitutively activate Akt1 gene can prolong graft survival during early posttransplant period, and can accelerate the revascularization of islet grafts effectively.
【Abstract】Objective To investigate the effects of preservative temperature on pancreatic function and determine the optimal preservative temperature for pancreatic transplantation. MethodsCold pancreatic preservation was performed and a homologous male Wistar rat model of heterotopic total pancreaticoduodenal transplantation was established. The pancreas was preserved for 6 h in UW solution at specific temperatures(0 ℃, 4 ℃, 8 ℃ and 12 ℃). After preservation, pancreatic tissue was taken for histologic examination in every group. ATP and total adenine nucleotides (TAN) were determined by using high performance liquid chromatography (HPLC). Blood glucose(BG), serum amylase and lipase were measured 24 h after transplantation. And the activity of myeloperoxidase (MPO) in the pancreatic grafts was also measured at the same time. Besides, histological observation was performed. Results Microscopic studies showed that the histomorphological changes of pancreas in 4 ℃ group were less obvious than those in other groups. Tissual concentrations of ATP and TAN decreased gradually in 4 ℃ group, 0 ℃ group, 8 ℃ group, and 12 ℃ group after 6 h of preservation(PH＜0.05). The levels of BG, serum lipase and MPO increased gradually in 4 ℃ group, 0 ℃ group, 8 ℃ group, and 12 ℃ group(PH＜0.05). The activity of MPO in 4 ℃ group （1.19±0.16 U/g ）was significantly lower than that of the control group（0.26±0.09 U/g，PH＜0.05). Conclusion The temperature of 4 ℃ is most appropriate for hypothermic pancreatic preservation and can considerably alleviate cold ischemic injury of rat pancreas.