Transplantation of mature islets into portal vein has been most effective thus far, although attrition of transplanted islets constitutes a major limitation, and alternative approaches are required. We analyzed the mechanisms by which islets engrafted, vascularized and functioned over the long term in the small intestinal submucosa. To determine engraftment, survival and function, 350 syngenic islets were transplanted into either intestinal segments or portal vein of diabetic rats. Islet reorganization, vascularization and function were analyzed by histological analysis, RT-PCR analysis as well as glycemic control over up to 1 year. Transplantation of syngeneic islets in marginal numbers successfully restored normoglycemia in diabetic rats. Transplantation of semi-pure islet preparation did not impair their engraftment, vascularization and function. Islets were morphologically intact and expressed insulin as well as glucagon over the year. Expression of angiogenic genes permitted revascularization of transplanted islets. We identified the expression of transcription factors required for maintenance of beta cells. These studies demonstrated that marginal mass of transplanted islets was sufficient to restore euglycemia in streptozotocin-treated rats. These superior results were obtained despite use of an impure preparation of islets in animals with small intestinal segment. Our findings will help advance new horizons for cell therapy in patients with diabetes.
SEM of corrosion casts (CC) provides the opportunities to study the vessels and ducts in the phyllogenetic and ontogenetic (age‐related) settings, as well as the pathogenesis, compensation, and sanogenesis in different diseases and experimental models. Along with the refinement of SEM CC, the requirements toward casting media (CM) as nontoxicity, low viscosity, quick polymerization, resistance to corrosion solutions, availability, and so on, gradually has developed. We aimed to adapt the sets widely used in dental practice toward the modern requirements to the CC. The following ratio of the components of Protacryl‐M and Aycryl‐C sets were used for the preparation CM—0.25 g MAYCRYL Powder +0.08 g Benzoyl Peroxide +5.0 ml Protacryl‐M liquid component +0.2 Redont Colour (dye concentrate). The obtained solidifying mass was injected in the blood vessels and biliary ducts of the adult Wistar white rats. The SEM of CC of different organs’ vascular networks, as well as a biliary tract, reveals that offered CM excellently replicates the forms and branching features of studied tubular structures of all sizes and gives the adequate imprinting of their luminal surfaces. Besides, CM may provide the replication of perivascular spaces and give the casts having no analogous in the appropriate literature. The CM prepared by us perfectly reproduces all possibilities of famous rubbers widely used for the casting of different vascular–ductular structures. Besides, it presents the new implications, which should be implemented in the profound research of the connective‐tissue skeleton of different organs.
Synthetic radioinert androgen methyltrienolone administered daily for 2 weeks to male rats with severe diabetes led to a sharp increase in blood testosterone and was accompanied by reduction in glucose level due to an increase in tissue sensitivity to insulin. Normalization of plasma testosterone concentration contributed to saturation of active androgen receptors in the myocardium with testosterone; the number of free receptors decreased by 1.8 times. Testosterone that diminishes the catabolic effects of glucocorticoids improved the state of the myocardium, which was confirmed by activation of DNA and RNA synthesis.
The study of the fractal architecture of various organs and structures expanded the possibilities for determining the ranges of their functioning and structural arrangement, which, as a result, was reflected in the development of new approaches to diagnostics and therapeutic impacts. The architecture of the excretory duct systems, similar to the hemo‐ and lymph‐ circulatory beds and the bronchial tree, is considered fractal. At the same time, information about hitherto unknown structures of the biliary tree continues to appear in the literature. We aimed to study the features of the spatial geometry of the biliary tree and assess the significance of both its fractal and Euclidean characteristics for the development of approaches that facilitate comprehensive description of intrahepatic biliary tract architecture. We investigated the architecture of the biliary trees of six men, seven male canines, and seven male Wistar rats using the corrosion casting method. Corrosion casts were prepared by injecting solidifying latexes into the bile ducts. The preparations were studied using a light stereomicroscope and a scanning electron microscope. Biliary tree branching is of various types. In addition, the correlation between variations in the caliber and length of the bile ducts and their order is not significant. Therefore, the biliary tree should not be considered as a classical fractal and it consists of the main modules, represented by the network of the bile canaliculi (first nonfractal module) and a biliary tree with a fractal branching (second module) that drains the bile canaliculi mesh and the additional modules represented by the mucosal biliary glands (in mammals with the gallbladder) or the periportal biliary plexus (in mammals without a gallbladder) and the aberrant biliary ducts. Such a configuration of the biliary bed should optimally ensure the smooth implementation of the physiological function of the liver, as well as its adaptation to different pathologies accompanied by biliary hypertension. It also might be considered in the diagnosis and assessment of ductular reaction, biliary regeneration, and/or carcinogenesis.
Aim: The aim of the study was to investigate the restoration of metabolic imbalance related with deficiency of insulin by the exogenous androgen supplementation in the experimental model of alloxan-induced diabetes in Wistar male rats. Methods: The experimental diabetes was induced by a single intraperitoneal administration of alloxan. The concentrations of glucose, immunereactive insulin, corticosterone, testosterone and estradiol were examined in blood, the intensity of DNA and RNA synthesis and androgen receptor expression were studied in the liver Results:The induction of diabetes increased the concentrations of glucose, corticosterone and estradiol while decreases insulin and testosterone concentration in blood as well as DNA/RNA synthesis and androgen receptors expression in hepatocytes. The administration of exogenous androgen significantly restored the metabolic imbalance and the expression of androgen receptors and increased DNA/RNA synthesis in liver cells maintained close to control level. Conclusion: The administration of methyltrienolone reduced the effect of "diabetic stress" and restored the hormonal dysfunction induced by alloxan.
The Influence of androgens on diabetes mellitus is a subject of extensive discussion. Testosterone effect in clinical trials commonly is evaluated in patients with diabetes type 2. In addition, the studies conducted on experimental models of diabetes (alloxan-and streptozotocininduced diabetes) also showed positive effects of androgen. Considering that experimental diabetes is more in line with diabetes type 1, it can be assumed that male sex hormone positively effects both types of diabetes. However, its influence may be realized by different pathways. Therefore, research of the opportunity of treatment of the various forms of diabetes with androgens, represents the active scientific and practical feature, which is waiting for the final verdict.
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