L. N. Ivanova

Serum corticosteroid-binding globulin levels in children undergoing heart surgery

Serum corticosteroid-binding globulin (CBG) levels were measured in children (mean age 4 years) during heart surgery. Considerable decrease in CBG level occurred between baseline examination (416 +/- 39 nM) and the day of surgery (314 +/- 30 nM). Relatively simple closed heart surgery did not influence CBG level with maximal cortisol level being 20 +/- 4 micrograms/dl. Open heart surgery under conditions of profound hypothermia (26 C, without extracorporeal circulation) caused dramatic lowering of CBG level, particularly striking after resuscitation (180 +/- 20 nM). At the same time cortisol level reached extremely high values (78 +/- 8 micrograms/dl). These data suggest that CBG is likely to play an important role in pituitary-adrenal response to surgery under severe conditions of hypothermia and cardiac arrest.

Effect of vasopressin on the expression of genes for key enzymes of hyaluronan turnover in Wistar Albino Glaxo and Brattleboro rat kidneys

•  What is the central question of this study? The interstitium of the renal inner medulla contains abundant linear negatively charged glycosaminoglycan hyaluronan (HA), which affects the water flow depending on their polymeric state. It remains an open question whether HA is involved in the long‐term effect of vasopressin on water reabsorption via the regulation of the expression of genes for key enzymes of HA turnover. •  What is the main finding and its importance? Using real‐time RT‐PCR, we show that in rats vasopressin inhibits the synthesis of HA and concomitantly promotes its degradation in the renal interstitium through its effect on genes for key enzymes of HA turnover (hyaluronan synthase‐2 and hyaluronidase‐2). Analysis of the long‐term effect of vasopressin on the transcription of these genes demonstrated a new mechanism in hormonal regulation of the renal concentrating function.

Russia's Northern Fishery Basin: Trends in Regulation, Fleet, and Industry

This paper reviews the most important changes that have taken place in Russias Northern fishery basin—the largest fishery in European Russia and a mainstay of northwest Russias economy—since the break-up of the Soviet Union. The authors first discuss the influence on fisheries management of various federal and regional bodies of governance. They then discuss the effects of the chosen regulation strategies on the structure of the fishing fleet, delivery of catches, and the onshore fish-processing industry in northwestern Russia.

Effect of hypoosmotic shock on the volume of renal collecting duct epithelial cells of brattleboro rats with hereditarily defective vasopressin synthesis.

102 The problem of maintaining a constant volume under conditions of extracellular and intracellular osmotic pressure fluctuations is particularly relevant for transport epithelium cells, such as renal collecting duct cells. The mechanisms regulating the cell volume in osmotic shock are specific for hypotensive and hypertensive effects [1, 2]. Recent studies have shown that the swelling rate of the cell in a hypoosmotic envii ronment and the effectiveness of regulatory volume decrease largely depend on the water permeability of the plasma membrane. The lipid bilayer of the cell membrane is highly permeable for water molecules due to the presence of specific proteins that form water channels (aquaporins, AQPs) [3]. Thus, the regulation of the water permeability of the cell membrane affects the parameters of the regulatory volume decrease (RVD). The transepithelial water permeability of renal collecting ducts increases as a result of AQP2 insertion into the apical membrane of cells in response to the neurohypophysial hormone vasopressin [4]. In the absence of the hormone or in the case of its inability to bind to receptors, the urine output and, respectively, the bodys fluid demands increase tenfold. In Brattlee boro rats, derived from LonggEvans rats [5], a single deletion in the vasopressin gene was found [6], which leads to disruption of the hormone synthesis [5, 7, 8]. Homozygous Brattleboro rats are characterized by a sharp decrease in the concentrating ability of the kidd neys, polydipsia, and polyuria. In this study, we invess tigated the effect of the absence of endogenous vasoo pressin in Brattleboro rats in response to changes in the volume of the principal cells of renal collecting ducts exposed hypoosmotic environment. The experiments were performed on Brattleboro and Wistar rats of both sexes. All animals were obtained from the laboratory of experimental animals, Russian Academy of Sciences (Novosibirsk). Experii ments were performed with adult 600dayold animals of the corresponding line, weighing 200–250 g. On the day of the experiment, animals were placed into mett abolic cages. The osmolarity of their spontaneously excreted urine samples was determined cryoscopically using an OSMETTE microosmometer (Precision Syss tems Inc., United States). Before the experiment, Brattleboro rats were kept under standard conditions and received dry food and water ad libitum. In experii ments we used the rats that drank a water amount that exceeded 50% of their body weight per day, which indii cated that they were homozygotes. The osmolality of spontaneously excreted urine was …

The effect of vasopressin on the expression of genes of key enzymes of the interstitial hyaluronan turnover and concentration ability in WAG rat kidneys

In mammals arginine-vasopressin (AVP) is a major hormone involved in the regulation of renal water reabsorption, acting via the increase of the osmotic permeability of the epithelium of the collecting duct. The AVP-induced intracellular events include, as a core step, the trafficking of the vesicles containing the water channels, aquaporin-2, to the apical plasma membrane of the collecting duct’s principal cells. The interstitium of the renal inner medulla contains abundant linear negatively charged glycosaminoglycan, hyaluronan (HA), which affects the water flow between structures of the concentrating mechanism, depending on its polymeric state. Using real-time RT-PCR, we tested the assumption that the renal hyaluronan may be involved in the long-term vasopressin effect on water reabsorption. The expression of the genes encoding hyaluronan synthase-2 (Has2), hyaluronidase-1, and hyaluronidase-2 (Hyal1 and Hyal2) in the kidneys of Wistar Albino Glaxo (WAG) was studied. The Has2 mRNA content was the highest in the papilla of the kidneys of the hydrated rats. The V2 receptor-selective vasopressin analog dDAVP (100 μg/kg of body weight, twice a day intraperitoneally for 2 days) induced a considerable decrease in the Has2 mRNA content in the papilla with less pronounced changes in the cortex. In contrast to Has2, the dDAVP treatment caused a significant increase in the Hyal1 and Hyal2 mRNA content in the renal papilla. There was a good fit between the Hyal1 and Hyal2 transcriptional levels and changes in hyaluronidase activity in the renal tissue. It was suggested that vasopressin is able to inhibit the synthesis of hyaluronan and concomitantly promotes its degradation in the renal papilla interstitium, thereby facilitating water flow between the elements of the renal countercurrent system. The implications for this effect are discussed in the context of the data in the literature.

Pattern RT1A and proteasome expression in cellular fractions of Zajdela ascitic hepatoma.

152 The key problem of experimental and clinical oncology today is the identification of possible mech anisms affecting the progression and regression of malignant neoplasms. The realization of these mecha nisms includes both innate and adaptive immunity: natural killer cells (NK cells), macrophages, neutro phils, eosinophils, dendritic cells, various cytokines, and specific cytotoxic T cells [1]. One of the molecular mechanisms underlying tumor development may be a reduced effectiveness of presentation and recognition of oncoantigens by the immune system. An important role in the generation of antigenic peptide epitopes, forming complexes with the major histocompatibility complex (MHC) class I molecules for their presenta tion to cytotoxic T cells of the CD8 phenotype, is played by immune proteasomes [2, 3]. We have previ ously shown that an increase in the level of immune proteasomes and a decrease in the level of constitutive proteasomes are accompanied by regression of Walker 256 carcinosarcoma, transplanted to Brattleboro rats with a genetically defective synthesis of arginine vaso pressin [4]. At the same time, the change in the ratio of multiple forms of proteasomes towards the decrease in the content of immune proteasomes causes an active growth of Krebs II ascitic carcinoma in mice [5]. The expression of immune proteasomes is correlated with the expression of MHC class I antigens. Low expres sion of MHC class I antigens promotes the escape of tumor growth from the immune control and is charac teristic of such tumors as melanomas, prostate adeno carcinoma, and breast cancer [3, 6]. Cases when a low expression of MHC class I antigens was caused by dis turbances in the system of antigen preparation and pre sentation (in particular, at low expression of the immune proteasome subunits) were described [3, 4, 7]. However, studies providing evidence in favor of this assumption are rare.

Northwest Russian Fisheries After the Disintegration of the USSR: Market Structure and Spatial Impacts

After the early 1990s the position of the Northwest Russian fisheries in the global system of fisheries changed completely. Although the Soviet Union had established a Northern fisheries system based on global harvesting and deliveries to Russian regional “markets,” the new Northwest Russian system is based on catches in regional waters and access to global fish markets. In the same period, Northern fisheries units that formerly functioned as power centers of the Soviet fisheries system almost disappeared and were replaced by organisations embedded at the federal level. Here we analyze the shaping of the new spatial system of Russian fisheries, and its linkages with the introduction of market mechanisms after 1990. The most dramatic change occurred in 2000, when a state‐driven market experiment in form of quota auctions was introduced.

Role of the low-selective organic anion transport in regulation of osmotic balance of renal collecting duct principal cells under hypo-osmotic conditions

In the course of adaptation of the rat kidney collecting duct cells to hypo-osmotic medium, the organic anion transporter inhibitor probenecid reduced significantly the regulatory cell volume decrease in response to a hypotonic shock. Both probenecid and hypotonic shock delayed significantly the entry into a cell of the fluorescent dye calcein, which exists as anion at neutral pH. Thus, the organic osmolyte transport plays an important role in the regulatory decrease of the principal cell volume under the hypo-osmotic conditions.

Regulation of V2 receptor by vasopressin is different in Brattleboro rats compared with Wistar.

This paper presents the new priority data on the effect of genetically determined deficiency of endogenous vasopressin on the functioning of V2 receptor in the plasma membrane of the principal cells of the collection ducts of Brattleboro rats. It was found that 2-day desmopressin administration results in the activation of V2 receptor gene expression in Brattleboro rat, whereas in Wistar rats the content of mRNA did not change. In addition, short-term exposure of the collection ducts of the kidneys to the hormone led to V2 receptor internalization from the plasma membrane in Wistar rats, but had no effect on the protein content in Brattleboro rats.