AIM: To determine whether insulin could promote sinusoidal endothelial cell (SEC) proliferation mediated by upregulation of vascular endothelial growth factor (VEGF) in regenerating rat liver after partial hepate...AIM: To determine whether insulin could promote sinusoidal endothelial cell (SEC) proliferation mediated by upregulation of vascular endothelial growth factor (VEGF) in regenerating rat liver after partial hepatectomy (PHx). METHODS: Adult male Sprague-Dawley rats undergoing 70% PHx were injected with insulin (300 MU/kg) or saline via the tail veins every 8 h after surgery for 7 d and killed at 0, 24, 48, 72, 96, 120, 144, and 168 h after surgery. Proliferation of both hepatocytes and SECs was monitored by evaluating the proliferating cell nuclear antigen (PCNA) labeling index (LI). The expression of VEGF protein was evaluated by immunohistochemistJv. The mRNA expressions of VEGF and its receptors FIt-1 and FIk-1 were evaluated by semi-quantitative reverse transcription-PCR. RESULTS: Insulin markedly increased the expression of VEGF mRNA between 24 and 120 h after hepatectomy compared to controls. Similarly, insulin significantly increased the expression of Fit-1 between 24 and 96 h. However, insulin had no significant effect on FIk-1. Furthermore, the immunohistochemical staining revealed that expression of VEGF protein increased in the insulin groups. Insulin significantly increased the PCNA LI of hepatocytes and SECs compared to controls. CONCLUSION: Exogenous insulin may promote SEC proliferation with an enhanced expression of VEGF and its receptor Fit-1 in regenerating rat liver after PHx.展开更多
Persistent hyperinsulinemic hypoglycemia is caused most commonly by an insulinoma in adults or by nesidioblastosis in neonates. In adults, nesidioblastosis is a rare disorder characterized by diffuse or disseminated p...Persistent hyperinsulinemic hypoglycemia is caused most commonly by an insulinoma in adults or by nesidioblastosis in neonates. In adults, nesidioblastosis is a rare disorder characterized by diffuse or disseminated proliferation of islet cells. We recently encountered a case of nesidioblastosis in an adult. A 71-year-old man was admitted due to intermittent general weakness, abdominal pain, and mild dyspnea. The patient underwent a subtotal gastrectomy for a gastric adenocarcinoma two years ago. After 5 d of admission, the patient showed symptoms of cold sweating, chilling, and hypotension 30 min after eating. Thereafter, he frequently showed similar symptoms accounting for hypoglycemia regardless of food consumption. Laboratory findings revealed a low fasting blood glucose level (25 mg/dL), and a high insulin level (47 μIU/mL). Selective intra-arterial calcium stimulation with hepatic venous sampling (ASVS) was performed to localize a mass and revealed an increased insulin level about fourfold that of the normal fasting level at 60 s in the splenic artery, which suggested the presence of an insulinoma in the tail of pancreas. A distal pancreatectomy was performed. Neither intraoperative exploration nor a frozen biopsy specimen detected any mass-forming lesion. On the histological examination, many of the islets were enlarged and irregularly shaped in all specimens, the arrangement of which was a Iobulated islet pattern. Cytologically, a considerable subpopulation of endocrine cells showed enlarged and hyperchromatic nuclei. By immunohistochemistry, the cells were identified as p-cells. These clinical, radiological, microscopic and immuno-histochemical findings are consistent with diffuse nesidioblastosis in adults.展开更多
文摘AIM: To determine whether insulin could promote sinusoidal endothelial cell (SEC) proliferation mediated by upregulation of vascular endothelial growth factor (VEGF) in regenerating rat liver after partial hepatectomy (PHx). METHODS: Adult male Sprague-Dawley rats undergoing 70% PHx were injected with insulin (300 MU/kg) or saline via the tail veins every 8 h after surgery for 7 d and killed at 0, 24, 48, 72, 96, 120, 144, and 168 h after surgery. Proliferation of both hepatocytes and SECs was monitored by evaluating the proliferating cell nuclear antigen (PCNA) labeling index (LI). The expression of VEGF protein was evaluated by immunohistochemistJv. The mRNA expressions of VEGF and its receptors FIt-1 and FIk-1 were evaluated by semi-quantitative reverse transcription-PCR. RESULTS: Insulin markedly increased the expression of VEGF mRNA between 24 and 120 h after hepatectomy compared to controls. Similarly, insulin significantly increased the expression of Fit-1 between 24 and 96 h. However, insulin had no significant effect on FIk-1. Furthermore, the immunohistochemical staining revealed that expression of VEGF protein increased in the insulin groups. Insulin significantly increased the PCNA LI of hepatocytes and SECs compared to controls. CONCLUSION: Exogenous insulin may promote SEC proliferation with an enhanced expression of VEGF and its receptor Fit-1 in regenerating rat liver after PHx.
文摘Persistent hyperinsulinemic hypoglycemia is caused most commonly by an insulinoma in adults or by nesidioblastosis in neonates. In adults, nesidioblastosis is a rare disorder characterized by diffuse or disseminated proliferation of islet cells. We recently encountered a case of nesidioblastosis in an adult. A 71-year-old man was admitted due to intermittent general weakness, abdominal pain, and mild dyspnea. The patient underwent a subtotal gastrectomy for a gastric adenocarcinoma two years ago. After 5 d of admission, the patient showed symptoms of cold sweating, chilling, and hypotension 30 min after eating. Thereafter, he frequently showed similar symptoms accounting for hypoglycemia regardless of food consumption. Laboratory findings revealed a low fasting blood glucose level (25 mg/dL), and a high insulin level (47 μIU/mL). Selective intra-arterial calcium stimulation with hepatic venous sampling (ASVS) was performed to localize a mass and revealed an increased insulin level about fourfold that of the normal fasting level at 60 s in the splenic artery, which suggested the presence of an insulinoma in the tail of pancreas. A distal pancreatectomy was performed. Neither intraoperative exploration nor a frozen biopsy specimen detected any mass-forming lesion. On the histological examination, many of the islets were enlarged and irregularly shaped in all specimens, the arrangement of which was a Iobulated islet pattern. Cytologically, a considerable subpopulation of endocrine cells showed enlarged and hyperchromatic nuclei. By immunohistochemistry, the cells were identified as p-cells. These clinical, radiological, microscopic and immuno-histochemical findings are consistent with diffuse nesidioblastosis in adults.