Aldosterone and vasopressin affect α- and γ-ENaC mRNA translation

Vasopressin and aldosterone play key roles in the fine adjustment of sodium and water re-absorption in the nephron. The molecular target of this regulation is the epithelial sodium channel (ENaC) consisting of α-, β- and γ-subunits. We investigated mRNA-specific post-transcriptional mechanisms in hormone-dependent expression of ENaC subunits in mouse kidney cortical collecting duct cells. Transcription experiments and polysome gradient analysis demonstrate that both hormones act on transcription and translation. RNA-binding proteins (RBPs) and mRNA sequence motifs involved in translational control of γ-ENaC synthesis were studied. γ-ENaC–mRNA 3′-UTR contains an AU-rich element (ARE), which was shown by RNA affinity chromatography to interact with AU-rich element binding proteins (ARE-BP) like HuR, AUF1 and TTP. Some RBPs co-localized with γ-ENaC mRNA in polysomes in a hormone-dependent manner. Reporter gene co-expression experiments with luciferase γ-ENaC 3′-UTR constructs and ARE-BP expression plasmids demonstrate the importance of RNA–protein interaction for the up-regulation of γ-ENaC synthesis. We document that aldosterone and the V2 receptor agonist dDAVP act on synthesis of α- and γ-ENaC subunits mediated by RBPs as effectors of translation but not by mRNA stabilization. Immunoprecipitation and UV-crosslinking analysis of γ-ENaC–mRNA/HuR complexes document the significance of γ-ENaC–mRNA–3′-UTR/HuR interaction for hormonal control of ENaC synthesis

A922 Sequential measurement of 1 hour creatinine clearance (1-CRCL) in critically ill patients at risk of acute kidney injury (AKI)

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Effect of estrogenization in the first day of life on the reproductive system in male rats

The aim of the present report was to investigate dynamics of morphological and functional changes in the reproductive system of male rats between 20th and 84th day of life, injected neonatally with a single dose of stilbestrol. Marked reduction in relative weights of testes and accessory sexual glands was demonstrated in various periods of life. This was associated with inhibition of spermatogenesis at the stage of primary spermatocytes and with morphological as well as functional alterations in epididymis? seminal vesicles and ventral prostate. In the serunl, high levels of LH and lowered testosterone levels were demonstrated

Effects of melatonin, testosterone and the two hormones administered in parallel on ventral prostate of the rat treated with stilbestrol in the first day of life

Effects of melatonin, testosterone and the two hormones administered in parallel on ventral prostate were examined in the rats treated with estrogens in the first day of life. Thirty-nine-day long hormonal stimulation with melatonin, testosterone or the two hormones in parallel was started in rats aged 20, 28, 35 or 45 days. A single dose of estrogens led to atrophy of ventral prostate when the animals reached maturity, which was associated with high LH levels and low testosterone levels in the serum. Melatonin accentuated estrogen-induced changes in prostate morphology of ventral prostate while initemporal administration of melatonin and testosterone led to a resultant effect of testosterone-induced stimulation and melatonin-induced inhibition

Effects of melatonin, testosterone and the two hormones administered in parallel on epididymis of the rat estrogenized with stilbestrol in the first day of life

Effect of melatonin, testosterone and of both hormones given in parallel on rat epididymis was tested in rats given a single dose of 1 mg stilbestrol on the first day of the life. The hormones were given daily for 39 days, beginning from the 20th or 28th day of life. The single dose of estrogen treatment resulted in epididymis atrophy, accompanied by changes in glandular epithelium and in its stroma, when the rats reached mature age (59 or 67 days of life). In such rats, LH gonadotropin level was elevated and testosterone level was decreased. Administration of melatonin failed to affect the changes induced by estrogen treatment. Administration of testosterone alone or of testosterone in parallel with melatonin caused the epididymis status to resemble more closely that seen in control animals. Efferent ductules of the testis (head of epididymis) were also demonstrated to be more sensitive to the performed experimental procedures than the duct of the epididymis (body and tail of the epididymis)

Morphometric studies on rat testes in the course of postnatal development

Computer-assisted analysis of histologic images of rat testis in the course of postnatal period demonstrated its stepwise development. Three stages of the development could be distinguished, associated with different number of Leydig cells and with distinct secretive activity of the cell, as reflected by serum testosterone levels

Stimuli-responsive lyotropic liquid crystalline nanosystems with incorporated poly(2-dimethylamino ethyl methacrylate)-b-poly(lauryl methacrylate) amphiphilic block copolymer

There is an emerging need to evolve the conventional lyotropic liquid crystalline nanoparticles to advanced stimuli-responsive, therapeutic nanosystems with upgraded functionality. Towards this effort, typically used stabilizers, such as Pluronics®, can be combined or replaced by smart, stimuli-responsive block copolymers. The aim of this study is to incorporate the stimuli-responsive amphiphilic block copolymer poly(2-(dimethylamino)ethyl methacrylate)-b-poly(lauryl methacrylate) (PDMAEMA-b-PLMA) as a stabilizer in lipidic liquid crystalline nanoparticles, in order to provide steric stabilization and simultaneous stimuli-responsiveness. The physicochemical and morphological characteristics of the prepared nanosystems were investigated by light scattering techniques, cryogenic-transmission electron microscopy (cryo-TEM), X-ray diffraction (XRD) and fluorescence spectroscopy. The PDMAEMA-b-PLMA, either individually or combined with Poloxamer 407, exhibited different modes of stabilization depending on the lipid used. Due to the protonation ability of PDMAEMA blocks in acidic pH, the nanoparticles exhibited high positive charge, as well as pH-responsive charge conversion, which can be exploited towards pharmaceutical applications. The ionic strength, temperature and serum proteins influenced the physicochemical behavior of the nanoparticles, while the polymer concentration differentiated their morphology; their micropolarity and microfluidity were also evaluated. The proposed liquid crystalline nanosystems can be considered as novel and attractive pH-responsive drug and gene delivery nanocarriers due to their polycationic content. © 2019 by the authors