Diabetes insipidus

Selection of desmopressin preparations for the treatment of central diabetes insipidus

Central diabetes insipidus (CDI) is a severe pathology of the hypothalamic-pituitary system, based on a deficit of antidiuretic hormone (ADH). The disease is a life threating condition for patients without adequate replacement therapy by various preparations of arginine vasopressin. This review presents the current concepts on etiology, pathogenesis, diagnostic proсedures, and treatment of CDI. The article gives comparative pharmacological characteristics of various desmopressin forms for the treatment of the central form of disease. When choosing a therapy for the treatment of CDI, the article highlights the long-term high efficiency and safety of the original sublingual form of desmopressin (Mininin Melt), which is confirmed by real clinical practice and clinical trials, including the comparison with other forms of desmopressin.

Effects of fucoidan on insulin stimulation and pancreatic protection via the cAMP signaling pathway in vivo and in vitro

Diabetes is a global disease, in which pancreatic dysfunction is an important pathological process. In previous years, interest in the biological activities of seaweed has increased. Fucoidan is an extract of the seaweed Fucus vesiculosus, which has been widely investigated. The present study aimed to determine the effects of fucoidan on insulin stimulation and pancreatic protection in vivo and in vitro. Goto‑Kakizaki (GK) rats were provided with free access to standard food, with or without fucoidan, for 13 weeks, following which the body weights, and blood glucose and serum insulin levels of the rats were measured. Wistar rats were used as a control. In addition, the RIN‑5F rat insulin‑secreting cell line was treated with fucoidan in high glucose conditions, following which the dose‑dependent and time‑dependent effects of fucoidan were determined, and the concentration of insulin was measured. Glybenclamide was used as a positive control. In vivo, the body weight and serum insulin levels decreased, whereas blood glucose levels increased significantly in the GK rats, compared with the Wistar control rats. Although, fucoidan did not improve changes in body weight, the increased blood glucose levels were reduced and the decreased serum insulin levels were increased in the GK rats following oral administration of fucoidan. In vitro, fucoidan did not exhibit significant cytotoxicity towards the RIN‑5F cells, and the insulin secretion increased significantly in a dose‑ and time‑dependent manner. Treatment with amylin, an islet amyloid polypeptide and glybenclamide inhibitor, did not inhibit the stimulatory activity of fucoidan. The results of the present study also demonstrated that the concentration of cyclic adenosine monophosphate (cAMP) was significantly increased in the fucoidan‑treated RIN‑5F cells, and this increase was dose‑ and time‑dependent. In addition, treatment with a phosphodiesterase inhibitor, which decreases the degradation of cAMP, significantly increased fucoidan‑induced insulin secretion, whereas treatment with an adenylyl cyclase inhibitor, which decreases the generation of cAMP, significantly decreased fucoidan‑induced insulin secretion. In conclusion, these data indicated that fucoidan may stimulate insulin secretion and provide pancreatic protection via the cAMP signaling pathway, in vivo and in vitro.

Influence of vanadium-organic ligands treatment on selected metal levels in kidneys of STZ rats

The objective of the study was to investigate the effects of five organic vanadium complexes supplement and a small dose of insulin injection on V, Fe, Cu, Zn, Mn, Ca, and K level in the streptozotocin diabetic rat's kidney during a 5-week treatment with the tested complexes. In all groups of animals, metal level in the lyophilized kidney organs was investigated by means of the proton induced X-ray emission method. Tissue vanadium level was naturally higher in vanadium-treated rats. The maximum level of vanadium was observed in the kidney (x(mean) = 16.6 μg/g). The influence of vanadium administration on other metal level in rat's tissue was also investigated. Spectacular influence of vanadium action was observed on copper and zinc level in examined tissue.

Deficiency of the tetraspanin CD63 associated with kidney pathology but normal lysosomal function

CD63 is a member of the tetraspanin superfamily that constitutes a main component of the lysosomal membrane. In mice, two CD63 gene loci are present, with only one of these two being functional. We generated and analyzed mice deficient for active CD63. Disruption of CD63 results in a complete loss of CD63 protein expression. Despite its abundance in late endosomes/lysosomes, the lack of CD63 does not cause obvious endosomal/lysosomal abnormalities. CD63 knockout mice are viable and fertile without gross morphological abnormalities in the majority of tissues. No alterations in the populations of immune cells and only minor differences in platelet function were observed. This suggests that the lack of CD63 could be successfully compensated for, most likely by other tetraspanins. However, CD63 deficiency leads to an altered water balance. CD63 knockout mice show an increased urinary flow, water intake, reduced urine osmolality, and a higher fecal water content. In principle cells of the collecting duct of CD63-deficient mice, abnormal intracellular lamellar inclusions were observed. This indicates that the sorting of apical transport proteins might be impaired in these cells. CD63 knockout mice provide an important tool for analyzing the various postulated functions of CD63 in vivo.

Cerebral salt wasting syndrome: review

Hyponatremia is the most frequent electrolyte disorder in critically neurological patients. Cerebral salt wasting syndrome (CSW) is defined as a renal loss of sodium during intracranial disease leading to hyponatremia and a decrease in extracellular fluid volume. The pathogenesis of this disorder is still not completely understood. Sympathetic responses as well as some natriuretic factors play a role in this syndrome. Distinction between SIADH and CSW might be difficult. The essential point is the volemic state. It is necessary to rule out other intermediate causes. Treatment requires volume replacement and maintenance of a positive salt balance. Mineral corticoids may be useful in complicated cases.