Objective To study the advances in microcirculation after islets of Langerhans transplantation (ILT). Methods The literature in the recent years on the study of the relationship between ILT and microcirculation was reviewed. Results The process of angiogenesis and revascularization of the islet grafts was in progress within 1 week after transplantation, and was completed within 10-14 days after transplantation, exhibiting a microangioarchitecture similar to pancreatic islets in situ. The sequence of vascular intraislet cellular perfusion was from β cells outward to α-and δ-cell cortex, with the majority of α cells perfused before the majority of δ cells. Freely transplanted islet grafts were revascularized from the hostderived microvascular bed. The interstitial pressure in the islet transplants was markedly lower than the capillary pressure. There were clearly differences in microcirculation between syngeneic and xenogeneic islet grafts. The phenomena of microcirculation failure were observed in xenografts. The influential factors of microcirculation after ILT were ①culture temperature of isolated islets, ②cultured time and cryopreserved method of islets, ③blood glucose, ④immunosuppressive agents, ⑤angiogenesis factors. Conclusion Microvascularization of freely islet grafts is one of the essential requirements for successful engraftment, guaranteeing sufficient nutritional blood supply to the tissue and establishing blood drainage for adequate liberation of the endocrine hormones. Through the studies of the microcirculation after ILT, it is helpful to recognize the mechanism of the survival of islet grafts.
ObjectiveTo explore the effects of urinastatin(UTI) on microcirculation of extrapancreatic organs in rats with acute necrotizing pancreatitis(ANP). Methods A total of 48 rats were randomized into control group, ANP group and UTI group. The model of ANP was established by uniform injection of 5% sodium taurocholate solution under pancreatic capsule, only injection of normal saline in control group. Then the rats of UTI group were injected with UTI through the femoral vein, the rats of ANP group and control group were injected with normal saline. The blood flow of lung, kidney and distal small intestine was measured by radioactive biomicrosphere technique at 2 h and 6 h after ANP.ResultsCompared with the control group, the blood flow of lung, kidney and intestine was decreased significantly in the ANP group at the 2 h and 6 h after ANP （P＜0.05）, compared with the ANP group, the blood flow was increased significantly in UTI group （P＜0.05）. ConclusionMicrocirculation disorder is an important factor of the extrapancreatic organ damage in ANP, and UTI plays a protective role against microcirculation disorder of the extrapancreatic organ in ANP.
In order to investigate the survival mechanism and the role of venous drainage in arterialized venous skin flap, 60 rabbits’ ears were used for research and clinical application of the flap was performed subsequently in two cases. The rabbits were divided into 4 groups. Experimental group was standard arterialized venous skin flap, control 1 group was venous skin flap, control 2 group was arterialized venous skin flap with only one drainage vein and control 3 group was normal skin flap. The process of survival of the flaps was observed by hemodynamic and histological method. The results showed that there was no significant difference between standard arterialized venous skin flap and normal skin flap (P gt; 0.01). Two cases of arterialized venous skin flap survived completely. The conclusion were as follow: 1. the opening of collateral circulation between the veinlets was the main change of the microcirculation; 2. the blood flow of the graft was changed from unphysiological circulation to physiological circulation as the time elapsed and 3. amelioration of venous drainage was important in inproving the survival rate of arterialized vein graft.
【Abstract】Objective To study the change of pancreatic microcirculation in the early phase of acute pancreatitis. MethodsLiteratures on acute pancreatitis and microcirculation were collected and reviewed.ResultsPancreatic microcirculation has changed in the early phase of acute pancreatitis, including contraction of interlobular arteriole, slowing of blood fluid, increasing of pancreatic vascular permeability, leukocyte adherence in postcapillary venules, and decreasing of pancreatic perfusion.Conclusion Impairment of pancreatic microcirculation in the early phase of acute pancreatitis may play a key role in the progression of this disease.
Objective To observe and analysis the features of images of fundus fluorescein angriography (FFA) in low-perfused retinopathy caused by cephalo-cervical peripheral vascular stenosis or occlusion. Methods The results of FFA of 27 patients diagnosed with carotid artery stenosis or occlusion by digital subtraction angiography (DSA) and examination of Doppler and vascular-pulsation were retrospectively analyzed. Result All of the patients had a delayed arm-retinal circulation duration from 20.0 to 81.08 seconds with the mean of 32.1 seconds; a delayed retinal arteriovenous filling duration from 6 to 64.0 seconds with the mean of 24.2 seconds. Delayed arm-retinal circulation duration and retinal a rteriovenous filling duration in 10 cases (37.0%); microangioma, vascular wall staining, nonperfused capillary area in 11 (40.7%); and anterior ischemic syndrome in 6 (22.2%) were found. In the 6 patients with anterior ischemic syndrome, 4 cases had narrow retinal artery, segmental changes of blood stream, vascular atresia, and abnormal arterio-venous anastomosis, and 2 cases had bold vascular loops. Conclusions The main manifestations of FFA in patients with low-perfused retinopathy are malperfusion and retinal ischemia, whose degrees relate to the extend of carotid artery stenosis or atresia, and the process of the disease.Serious retinal ischemia may combined with anterior ischemic syndrome. (Chin J Ocul Fundus Dis，2004，20：84-86)
Anti-VEGF therapies have been widely used in the treatment of age-related macular degeneration, diabetic macular edema, retinal vein occlusion with macular edema and other retinal diseases. It have achieved remarkable treatment effect with relatively high safety, but there are still reports of adverse reactions in cardio-cerebral vessels and eyes. There are many methods to measure retinal blood flow. Although the principles of these methods are different, the results are different, and there is no uniform standard, it has been observed that anti-VEGF drugs may cause some changes in retinal vessel diameter, arterial blood flow velocity and blood flow parameters. Especially after multiple injections, the effect may be more obvious.
Objective To investigate the relationship between gene expression of endothelin-3 (ET-3） and inflammation of acute pancreatitis （AP） in rats. Methods Fifty-four rats were divided randomly into 4 groups: sham operation group, AP group, arterial injection group and vein injection group. AP was induced by reverse intra-bile duct infusion 4.5% sodium taurocholate, treated with low dose dopamine 〔5 μg/（kg·min）〕 by injecting arterial or tail vein. Rats were sacrificed at 1， 6 and 24 h after the induction of AP. The mRNA expression of ET-3 was evaluated by semi-quantitative reverse transcription-polymerase chain reaction (RT-PCR) and pathological changes was observed in rats. Results Expression of ET-3 mRNA could be detected from 1 up to 24 h after the induction of pancreatitis. Expression of ET-3 mRNA of sham operation group was decreased significantly compared with other three groups. Expression of ET-3 mRNA showed a significant decrease by arterial injection dopamine than that by tail vein (P＜0.05， P＜0.01). The pathologic score in AP group was the highest, vein injection group was the next one, and score in sham operation group was the lowest. Conclusion There are significant relationship between inflammation of AP and expression of ET-3 mRNA. Dopamine administration by arterial injection is more effective than that by tail vein injection.
Objective To explore the effect of renal microcirculation following severity acute pancreatitis （SAP） on renal injury and to explore the protection effect of urokinase on them. Methods A total of 192 Wistar rats were randomized divided into normal control group， SAP group， and urokinase group， then rats of 3 groups were sub-divided into 2， 6， 12， and 24 hours group， each group enrolled 16 rats. Of the 16 rats in each subgroup， 8 rats underwent blood flow of renal test， other 8 rats were sacrificed to get blood samples and to perform histopathological examination. The rat models of SAP were established by retrograde injecting with 5% sodium taurocholate into the cholangiopancreatic duct. Radioactive biomicrosphere technique was used to measure the blood flow of renal， levels of plasma thromboxane B2（TXB2） and 6-keto-prostaglandin F1α （6-Keto-PGF1α） were tested by the TXB2 kit and 6-Keto-PGF1α kit， and histopa-thological changes of renal tissues were observed by using HE staining. Results Compared with normal control group at the same time point， the blood flow of renal were lower （P＜0.05）， activity ratio of TXB2 to 6-Keto-PGF1α were higher（P＜0.01）， and the histopathological injury were worse （P＜0.01） in rats of SAP group and urokinase group. Compared with SAP group， the blood flow of renal at 2， 6， and 12 hours in urokinase group were higher （P＜0.01）， the activity ratios of TXB2 to 6-Keto-PGF1α were lower （P＜0.01）， and the histopathological injury were lighter （P＜0.05） in all the 4 time points of urokinase group. Conclusions The renal microcirculation dysfunction and increase of activity ratio of TXB2 to 6-Keto-PGF1α may play an important role in renal injury following SAP in early stage. Urokinase can protect the renal from such injuries.
In order to study the influence of reperfusion following ischemia on microvesseles and microcirculation of skeletal muscle, unilateral hindlimbs of 16 rabbits were subjected to normothermic ischemia for 2 and 5 hours by tourniquet. After release of the tourniquet, microcirculation of the peritenon on dorsum of the foot was observed for 1 hours by intravital microscope. At 1 hour and 72 hours following reperfusion, the anterior tibia muscle biopsiy were taken and the specimens were subjected to light and electron microscopic examinations. It was found that after release of the tourniquet, in the limbs undergone 2 hours ischemia, there was immediate and well distributed reflow in the microvesseles of peritenon though a few aggregates of red cells and increase in the number of adherent leukocytes occured in some venules, and the microvesseles of the skeletal muscle only showed signs of minimal injury, the muscle fibers could survive in the limbs undergone 5 hours of ischemia, however, there was serious disturbance of microcirculation in theperitenon, which was characterized by "no reflow" in most area and there was signi ficant increase in the number of leukocytes adherent to venular endothelium, and the microvesseles of the skeletal muscle showed signs of severe injury, including remarkable swelling of the endothelial cell, disruption of the basement membrane and interstitial edema, and finally, most of the muscle fibers had necrosis occured. The results demonstrated that reperfusion following ischimia might result in microvascular injury and microcirculation disorder in the ischemic area. The degree of the injury and disorder depended on the duration of ischemic period, and was an important factor which determined the fate of the parenchymal cell.
The model of acut hemorrhagic necrotizing pancreatitis(AHNP)was produced by retrograde injection of 3% sodium taurocholate into the biliopancreatic duct.48rats with AHNP were treated with Tanshin by subcutaneous injection(100mg/100g body weight,q12h,tanshin group),48 rats with AHNP without any treatment as control(control group).The resule showed that in the control group,there were severe hemorrhage,necroses and the lesions of microvascular,the activity of pancreatic enzyme in serum increased significantly(Plt;0.01)at 6h,after 12h the activities of those pancreatic enzymes decreased gradually, the lesions of microvascular and histology were becoming severer.In the Tanshin group,at 24h the lesions of microvascular and histology of the pancreas were modified significantly (Plt;0.05).These results suggest that the lesion of microcirculation play an important role in the later AHNP,and Tanshin has some effects on the AHNP by modifying the microcirculation of the pancreas.