26
|
Kuznetsov NA, Kladova OA, Kuznetsova AA, Ishchenko AA, Saparbaev MK, Zharkov DO, Fedorova OS. Conformational Dynamics of DNA Repair by Escherichia coli Endonuclease III. J Biol Chem 2015; 290:14338-49. [PMID: 25869130 DOI: 10.1074/jbc.m114.621128] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2014] [Indexed: 11/06/2022] Open
Abstract
Escherichia coli endonuclease III (Endo III or Nth) is a DNA glycosylase with a broad substrate specificity for oxidized or reduced pyrimidine bases. Endo III possesses two types of activities: N-glycosylase (hydrolysis of the N-glycosidic bond) and AP lyase (elimination of the 3'-phosphate of the AP-site). We report a pre-steady-state kinetic analysis of structural rearrangements of the DNA substrates and uncleavable ligands during their interaction with Endo III. Oligonucleotide duplexes containing 5,6-dihydrouracil, a natural abasic site, its tetrahydrofuran analog, and undamaged duplexes carried fluorescent DNA base analogs 2-aminopurine and 1,3-diaza-2-oxophenoxazine as environment-sensitive reporter groups. The results suggest that Endo III induces several fast sequential conformational changes in DNA during binding, lesion recognition, and adjustment to a catalytically competent conformation. A comparison of two fluorophores allowed us to distinguish between the events occurring in the damaged and undamaged DNA strand. Combining our data with the available structures of Endo III, we conclude that this glycosylase uses a multistep mechanism of damage recognition, which likely involves Gln(41) and Leu(81) as DNA lesion sensors.
Collapse
|
27
|
Kuznetsov NA, Faleev NG, Kuznetsova AA, Morozova EA, Revtovich SV, Anufrieva NV, Nikulin AD, Fedorova OS, Demidkina TV. Pre-steady-state kinetic and structural analysis of interaction of methionine γ-lyase from Citrobacter freundii with inhibitors. J Biol Chem 2014; 290:671-81. [PMID: 25398880 DOI: 10.1074/jbc.m114.586511] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Methionine γ-lyase (MGL) catalyzes the γ-elimination of l-methionine and its derivatives as well as the β-elimination of l-cysteine and its analogs. These reactions yield α-keto acids and thiols. The mechanism of chemical conversion of amino acids includes numerous reaction intermediates. The detailed analysis of MGL interaction with glycine, l-alanine, l-norvaline, and l-cycloserine was performed by pre-steady-state stopped-flow kinetics. The structure of side chains of the amino acids is important both for their binding with enzyme and for the stability of the external aldimine and ketimine intermediates. X-ray structure of the MGL·l-cycloserine complex has been solved at 1.6 Å resolution. The structure models the ketimine intermediate of physiological reaction. The results elucidate the mechanisms of the intermediate interconversion at the stages of external aldimine and ketimine formation.
Collapse
|
28
|
Kuznetsova AA, Kuznetsov NA, Ishchenko AA, Saparbaev MK, Fedorova OS. Pre-steady-state fluorescence analysis of damaged DNA transfer from human DNA glycosylases to AP endonuclease APE1. Biochim Biophys Acta Gen Subj 2014; 1840:3042-51. [PMID: 25086253 DOI: 10.1016/j.bbagen.2014.07.016] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2014] [Revised: 07/08/2014] [Accepted: 07/22/2014] [Indexed: 12/26/2022]
Abstract
BACKGROUND DNA glycosylases remove the modified, damaged or mismatched bases from the DNA by hydrolyzing the N-glycosidic bonds. Some enzymes can further catalyze the incision of a resulting abasic (apurinic/apyrimidinic, AP) site through β- or β,δ-elimination mechanisms. In most cases, the incision reaction of the AP-site is catalyzed by special enzymes called AP-endonucleases. METHODS Here, we report the kinetic analysis of the mechanisms of modified DNA transfer from some DNA glycosylases to the AP endonuclease, APE1. The modified DNA contained the tetrahydrofurane residue (F), the analogue of the AP-site. DNA glycosylases AAG, OGG1, NEIL1, MBD4(cat) and UNG from different structural superfamilies were used. RESULTS We found that all DNA glycosylases may utilise direct protein-protein interactions in the transient ternary complex for the transfer of the AP-containing DNA strand to APE1. CONCLUSIONS We hypothesize a fast "flip-flop" exchange mechanism of damaged and undamaged DNA strands within this complex for monofunctional DNA glycosylases like MBD4(cat), AAG and UNG. Bifunctional DNA glycosylase NEIL1 creates tightly specific complex with DNA containing F-site thereby efficiently competing with APE1. Whereas APE1 fast displaces other bifunctional DNA glycosylase OGG1 on F-site thereby induces its shifts to undamaged DNA regions. GENERAL SIGNIFICANCE Kinetic analysis of the transfer of DNA between human DNA glycosylases and APE1 allows us to elucidate the critical step in the base excision repair pathway.
Collapse
|
29
|
Kuznetsov NA, Kuznetsova AA, Vorobjev YN, Krasnoperov LN, Fedorova OS. Thermodynamics of the DNA damage repair steps of human 8-oxoguanine DNA glycosylase. PLoS One 2014; 9:e98495. [PMID: 24911585 PMCID: PMC4049573 DOI: 10.1371/journal.pone.0098495] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2014] [Accepted: 05/03/2014] [Indexed: 11/19/2022] Open
Abstract
Human 8-oxoguanine DNA glycosylase (hOGG1) is a key enzyme responsible for initiating the base excision repair of 7,8-dihydro-8-oxoguanosine (oxoG). In this study a thermodynamic analysis of the interaction of hOGG1 with specific and non-specific DNA-substrates is performed based on stopped-flow kinetic data. The standard Gibbs energies, enthalpies and entropies of specific stages of the repair process were determined via kinetic measurements over a temperature range using the van’t Hoff approach. The three steps which are accompanied with changes in the DNA conformations were detected via 2-aminopurine fluorescence in the process of binding and recognition of damaged oxoG base by hOGG1. The thermodynamic analysis has demonstrated that the initial step of the DNA substrates binding is mainly governed by energy due to favorable interactions in the process of formation of the recognition contacts, which results in negative enthalpy change, as well as due to partial desolvation of the surface between the DNA and enzyme, which results in positive entropy change. Discrimination of non-specific G base versus specific oxoG base is occurring in the second step of the oxoG-substrate binding. This step requires energy consumption which is compensated by the positive entropy contribution. The third binding step is the final adjustment of the enzyme/substrate complex to achieve the catalytically competent state which is characterized by large endothermicity compensated by a significant increase of entropy originated from the dehydration of the DNA grooves.
Collapse
|
30
|
Balanovskiĭ OP, Koshel' SM, Zaporozhchenko VV, Pshenichnov AS, Frolova SA, Kuznetsova MA, Baranova EE, Teuchezh IE, Kuznetsova AA, Romashkina MV, Utevskaia OM, Churnosov MI, Villems R, Balanovskaia EV. [Genetic ecological monitoring in human populations: heterozygosity, mtDNA haplotype variation, and genetic load]. GENETIKA 2011; 47:1523-1535. [PMID: 22332410] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Yu. P. Altukhov suggested that heterozygosity is an indicator of the state of the gene pool. The idea and a linked concept of genetic ecological monitoring were applied to a new dataset on mtDNA variation in East European ethnic groups. Haplotype diversity (an analog of the average heterozygosity) was shown to gradually decrease northwards. Since a similar trend is known for population density, interlinked changes were assumed for a set of parameters, which were ordered to form a causative chain: latitude increases, land productivity decreases, population density decreases, effective population size decreases, isolation of subpopulations increases, genetic drift increases, and mtDNA haplotype diversity decreases. An increase in genetic drift increases the random inbreeding rate and, consequently, the genetic load. This was confirmed by a significant correlation observed between the incidence of autosomal recessive hereditary diseases and mtDNA haplotype diversity. Based on the findings, mtDNA was assumed to provide an informative genetic system for genetic ecological monitoring; e.g., analyzing the ecology-driven changes in the gene pool.
Collapse
|
31
|
Natochin IV, Kuznetsova AA. [Incretory function of the kidney]. USPEKHI FIZIOLOGICHESKIKH NAUK 2010; 41:28-43. [PMID: 20865936] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
Participation of kidney in maintenance of constancy of parameters of the organism internal medium is connected with formation in it of physiologically active substances. They are components of systems of regulation of water-salt balance, arterial pressure, blood coagulation, erythropoiesis. Mechanisms of normalization by kidney of concentration of hormones in blood and of modulation of action of hormones are analyzed.
Collapse
|
32
|
Natochin IV, Shestakova MV, Kuznetsova AA, Klefortova II, Trubitsyna NP, Dedov II. [Diabetes mellitus: renal osmoregulating function]. TERAPEVT ARKH 2010; 82:9-14. [PMID: 20731102] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
AIM To evaluate the kidney status from osmotic urine concentration in different stages of diabetes mellitus (DM) to define whether not only glomeruli and proximal tubules, but also renal medullary substance structures are involved into the pathological process, as well as their reaction to endogenous vasopressin production. SUBJECTS AND METHODS Forty patients with a 1-to-28-year history of DM, including 18 with diabetic nephropathy, 10 with chronic renal failure, and 22 without diabetic nephropathy, were examined. Urine and blood osmolality were determined and renal osmoregulating function was estimated. RESULTS Decreased glomerular filtration rate was found in relation to the duration of DM. The osmolality of nocturnal urine samples tended to diminish during short-term deprivation depending on the duration of DM. Increased diuresis in DM was shown to correlate with the higher reabsorption of osmotically free water. CONCLUSION Diminished renal concentrating capacity in DM appears to depend on evolving renal failure rather than vasopressin resistance. The application of a new approach, by calculating the clearance of sodium-free water, suggests that its increased reabsorption favors normalization of serum osmolality in hyperglycemia.
Collapse
|
33
|
Kuznetsova AA, Knorre DG, Fedorova OS. Oxidation of DNA and its components with reactive oxygen species. RUSSIAN CHEMICAL REVIEWS 2009. [DOI: 10.1070/rc2009v078n07abeh004038] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
|
34
|
Kuznetsova AA, Solov'eva LI, Fedorova OS. [Single-stranded DNA modification by an oligonucleotide-phthalocyanine Fe(II) conjugate: kinetic regulation and mechanism]. RUSSIAN JOURNAL OF BIOORGANIC CHEMISTRY 2009; 34:683-95. [PMID: 19060943 DOI: 10.1134/s1068162008050117] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Catalytic oxidative modification of single-stranded DNA with hydrogen peroxide and molecular oxygen in the presence of a conjugate containing an oligonucleotide complementary to the DNA fragment and tetra-4-carboxyphthalocyanine Fe(II) was studied. The conjugate examined was found to be active in the reaction of oxidative DNA cleavage in the presence of hydrogen peroxide, like earlier studied oligonucleotide conjugates containing tetra-4-carboxyphthalocyanine Co(II) and 2,4-di-[2-(2-hydroxyethyl)]deuteroporphyrin IX Fe(III) metallocomplexes generating active oxygen forms. The new conjugate was more active in the case of oxidation with molecular oxygen. Kinetic regularities and optimal regimes of DNA oxidation with hydrogen peroxide were found.
Collapse
|
35
|
Kuznetsova AA, Lukyanets EA, Solovyeva LI, Knorre DG, Fedorova OS. DNA-binding and oxidative properties of cationic phthalocyanines and their dimeric complexes with anionic phthalocyanines covalently linked to oligonucleotides. J Biomol Struct Dyn 2008; 26:307-20. [PMID: 18808197 DOI: 10.1080/07391102.2008.10507246] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Abstract
Design of chemically modified oligonucleotides for regulation of gene expression has attracted considerable attention over the past decades. One actively pursued approach involves antisense or antigene oligonucleotide constructs carrying reactive groups, many of these based on transition metal complexes. The complexes of Fe(II) and Co(II) with phthalocyanines are extremely good catalysts of oxidation of organic compounds with molecular oxygen and hydrogen peroxide. The binding of positively charged Fe(II) and Co(II) phthalocyanines with single- and double-stranded DNA was investigated. It was shown that these phthalocyanines interact with nucleic acids through an outside binding mode. The site-directed modification of single-stranded DNA by O2 and H2O2 in the presence of dimeric complexes of negatively and positively charged Fe(II) and Co(II) phthalocyanines was investigated. These complexes were formed directly on single-stranded DNA through interaction between negatively charged phthalocyanine in conjugate and positively charged phthalocyanine in solution. The resulting oppositely charged phthalocyanine complexes showed significant increase of catalytic activity compared with monomeric forms of phthalocyanines Fe(II) and Co(II). These complexes catalyzed the DNA oxidation with high efficacy and led to direct DNA strand cleavage. It was determined that oxidation of DNA by molecular oxygen catalyzed by complex of Fe(II)-phthalocyanines proceeds with higher rate than in the case of Co(II)-phthalocyanines but the latter led to a greater extent of target DNA modification.
Collapse
|
36
|
Shutskaia ZV, Shakhmatova EI, Kuznetsova AA, Natochin IV. [Role of the kidney in the regulation of osmolality and concentrations of cations in the blood serum in hyperglycemia]. FIZIOLOGIIA CHELOVEKA 2008; 34:73-79. [PMID: 18956564] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
|
37
|
Kuznetsova AA, Glushenko II, Shakhmatova EI, Natochin IV. [Vasopressin and prostaglandin E2 as regulators of uropoiesis during children's development]. FIZIOLOGIIA CHELOVEKA 2007; 33:46-54. [PMID: 17361606] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/14/2023]
|
38
|
Kanashkina TA, Kuznetsova AA, Shakhmatova EI, Natochin IV. [Role of V1- and V2-receptors in mechanism of physiological paradox--an increase of reabsorption of the solute free water and simultaneous rise of diuresis]. ROSSIISKII FIZIOLOGICHESKII ZHURNAL IMENI I.M. SECHENOVA 2006; 92:1228-38. [PMID: 17216720] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
In experiments on non-anesthetized rats with administration into stomach of water (5 ml/100 g body mass) direct correlation has been found between an increase of diuresis and excretion of solute free water (r = 0.98, p < 0.01), while after injection to these animals of 5 x 10(-11) M arginine-vasotocin - between an increase of diuresis and simultaneous rise reabsorption of solute free water (r = 0.8, p < 0.01). The rise of diuresis after the vasotocin injection is due to inhibition of sodium re- absorption, with the solute excretion fraction increasing from 2.6 +/- 0.2 % to 11.9 +/- 1.2, p < 0.001. A similar physiological paradox - an increase of diuresis with the simultaneous increase of reabsorption of solute free water - has been revealed at night hours in children with tendency for nocturnal enuresis (r = 0.64, p < 0.01). Mechanism responsible for this phenomenon consists in a rise of diuresis due to a decrease of sodium ion reabsorption in the ascending Henle loop limb. A problem is discussed of the homeostatic significance of a decrease of sodium reabsorption combined with an increase of solute-free water reabsorption; it is suggested that this phenomenon is based on a redistribution of reabsorption inside the nephron - a decrease of ion and water reabsorption in the initial parts of the nephron distal segment and an increase of solute free water reabsorption with the antidiuretic hormone-stimulated high osmotic permeability of terminal parts of renal tubules. An intraperitoneal injection of V1-anatagonist (OPC-21268) decreased the natriuretic component of response to arginine-vasotocin, while injection of V2-antagonist (OPC-31260) eliminated the antidiuretic component.
Collapse
|
39
|
Kuznetsova AA, Chernonosov AA, Kuznetsov NA, Koval VV, Knorre DG, Fedorova OS. Kinetic study of DNA modification by phthalocyanine derivative of the oligonucleotide. Bioinorg Chem Appl 2006; 2006:23560. [PMID: 17497004 PMCID: PMC1800914 DOI: 10.1155/bca/2006/23560] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2006] [Revised: 07/26/2006] [Accepted: 09/13/2006] [Indexed: 01/12/2023] Open
Abstract
Design of chemically modified oligonucleotides for regulation of gene expression has attracted considerable attention over the last decades. One actively pursued approach involves antisense or antigene constructs carrying reactive groups, many of these based on transition metal complexes. The complexes of Co(II) with phthalocyanines are extremely good catalysts of oxidation of organic compounds with molecular oxygen and hydrogen peroxide. In this study, we have investigated the kinetics and thermodynamics of sequence-specific modification of DNA with deoxyribooligonucleotide linked to Co(II)-tetracarboxyphthalocyanine (PtcCo(II)) in the presence of H(2)O(2).
Collapse
|
40
|
Kutina AV, Kuznetsova AA, Natochin IV. [Cations in the human blood serum]. USPEKHI FIZIOLOGICHESKIKH NAUK 2005; 36:3-32. [PMID: 16152785] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
The review summarizes data (more than 450 references) on concentration of human serum cations (Na+, K+, Ca2+, and Mg2+) and human blood serum osmolality depending on age, diverse physiological and pathological states, and action of physiologically active substances. There are summarized data of many thousand measurements of physicochemical parameters of the blood serum, the mean values of osmolality and cation concentrations in healthy people are calculated. The values are kept at a stable level throughtout the entire life since the moment of birth; in many cases they are maintained by regulatory systems within the normal limits and during various physiological and pathological states. There are formulated the main types of the states characterized by deviations from norm of physicochemical parameters of the internal medium fluids.
Collapse
|
41
|
Kuznetsova AA, Natochin IV. [Study of kidney functional development and regulation in children with pathologic processes]. ZHURNAL EVOLIUTSIONNOI BIOKHIMII I FIZIOLOGII 2005; 41:277-84. [PMID: 16033216] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
|
42
|
Kuznetsova AA, Natochin IV. [The study of physicochemical parameters of the blood serum and renal function in children with some pathology of the internal organs]. FIZIOLOGIIA CHELOVEKA 2004; 30:103-9. [PMID: 15344713] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 04/30/2023]
|
43
|
Kuznetsova AA, Natochin IV. [Physiological analysis of plasma hypo-osmolality in pneumonia]. TERAPEVT ARKH 2003; 74:56-60. [PMID: 12577843] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/28/2023]
Abstract
AIM To study the physiological mechanisms of plasma hypoosmolality in patients with pneumonia and on this basis to elaborate principles of therapy for this condition. MATERIALS AND METHODS 52 individuals of different age, including 26 patients with pneumonia, were examined. Osmolality, the concentrations of ions of sodium, potassium, magnesium, and creatinine were measured in the serum. RESULTS The patients with pneumonia were found to have osmolality, hyponatremia in combination with severe hypodiuresis, high urinary osmotic pressure and intensive reabsorption of osmotically free water in the kidney, which leads to blood dilution. As hypoosmolality usually causes higher diuresis and decreased urinary osmolality; hypodiuresis with high urinary osmolality in pneumonia is indicative of effective renal performance and its altered regulation evidently due to the hypersecretion of vasopressin or to the decreased formation of a number of autacoids in the kidney. CONCLUSION Blood hypoosmolality and hyponatremia in the examined patients result from inadequate blood osmolality and high urinary osmotic concentrating. The principles of this condition in pneumonia are discussed and aquaretics are proposed for use as pathogenetic therapy.
Collapse
|
44
|
Natochin YV, Bogolepova AE, Kuznetsova AA, Shakhmatova EI. Study of the role of prostaglandin E2 in urine flow regulation in chronic renal failure. SCANDINAVIAN JOURNAL OF UROLOGY AND NEPHROLOGY 2000; 34:327-30. [PMID: 11186473 DOI: 10.1080/003655900750048369] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
OBJECTIVE This study was carried out to investigate the role of prostaglandin E2 in the regulation of urine flow and ion excretion in patients with chronic renal failure. MATERIAL AND METHODS Twenty patients with chronic renal failure (CRF) and 13 healthy people were studied. CRF develops as a terminal stage of glomerulonephritis, pyelonephritis or polycystic renal disease. Osmolality and sodium, potassium, magnesium, calcium and creatinine concentrations were measured in urine and blood serum. Urine prostaglandin E2 was determined using kits for imminoenzyme analysis. RESULTS The average creatinine clearance was 19.9 +/- 6.3 ml/min, but it varied from 30 to 10 ml/min in different patients. In patients with CRF a correlation was revealed between diuresis and Na excretion (r = 0.78, p < 0.001) and between Na excretion and PGE2 excretion (r = 0.65, p < 0.001), a correlation that lacking in the healthy subject. A correlation was also found between diuresis and Mg excretion (r = 0.68, p < 0.001) and between Mg excretion and Na excretion (r = 0.83, p < 0.001) in patients with CRF but not in healthy subject. CONCLUSION It is suggested that in patients with CRF who experience a decrease in the glomerular filtration rate (to 75-90% of the normal value) the increase in urine flow is due to prostaglandin-dependent inhibition of ion reabsorption in the thick ascending limb of the loop of Henle.
Collapse
|
45
|
Bogolepova AE, Kuznetsova AA, Lukichev BG, Natochkin IV, Parshukova OI, Prutskova NP, Shakhmatova EI. [Mechanism f kidney participation in maintaining osmotic and ion homeostasis in chronic renal failure]. UROLOGIIA (MOSCOW, RUSSIA : 1999) 2000:5-8. [PMID: 11186713] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/19/2023]
Abstract
In examination of patients with chronic renal failure (CRF) at glomerular filtration rate below 30 ml/min and blood serum ion concentration within limits of normal values hyperosmia has been found. Under the natural regimen essential differences have been revealed neither in variation limits of renal excretion of ions nor osmotically active substances in CRF patients as compared with healthy controls. Diuresis correlated with renal excretion of osmotically active substances. It is shown that a decrease in reabsorption of osmotically active substances depends on secretion and excretion of prostaglandin E2. A suggestion is made about the role of prostaglandins in regulation of renal tubular function at terminal CRF stages.
Collapse
|
46
|
Kuznetsova AA, Shakhmatova EI, Prutskova NP, Natochin YV. Possible role of prostaglandins in pathogenesis of nocturnal enuresis in children. SCANDINAVIAN JOURNAL OF UROLOGY AND NEPHROLOGY 2000; 34:27-31. [PMID: 10757266 DOI: 10.1080/003655900750016841] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/16/2022]
Abstract
OBJECTIVE To compare excretion of ions and prostaglandins by the kidney in children with noctural enuresis. MATERIAL AND METHODS Thirty-two children with primary nocturnal enuresis and 23 normal children were examined. Osmolality and sodium and potassium concentrations were measured in their urine and blood serum. Prostaglandins E2, E1, and F2alpha were determined using kits for immunoenzyme analysis. Luminal and contraluminal prostaglandin secretions were studied in frog urinary bladder. RESULTS Children with nocturnal enuresis have increased nocturnal diuresis and renal sodium excretion, but no increase was found in excretion of prostaglandins E2, E1, and F2alpha. Administration of sodium diclofenac before bed-time eliminated episodes of nocturnal enuresis in 37% of children; intranasal administration of Adiuretin SD had a positive effect in 69% of enuretics. In children with nocturnal enuresis there is a correlation between renal excretion of PGE2 and sodium ions; this correlation is absent in the control group children, and disappears in enuretics treated with desmopressin. To evaluate the representativeness of the data on prostaglandin secretions to urine as compared with their release to extracellular fluid, experiments on frog urinary bladder were performed: a correlation was found between prostaglandin secretion to the urinary bladder lumen and to the extracellular fluid. CONCLUSIONS The results of the study suggest that changes in renal function are due not to a higher secretion of prostaglandins in nocturnal enuresis but to the relative dominance of their effect as compared with other physiologically active substances that simultaneously act on renal tubular cells.
Collapse
|
47
|
Abstract
Sixty-two children with nocturnal enuresis (43 boys, 19 girls aged 6-15 years) were treated with either desmopressin (Adiuretin-SD) (n = 32) or sodium diclofenac (n = 30). Desmopressin was effective in 85% of children and diclofenac in 33%. In children with primary nocturnal enuresis, the glomerular filtration rate was normal, whereas diuresis and solute excretion during the night were increased. Compared with healthy children, the nightly excretion of sodium was elevated by 43.7% and magnesium by 58.4%. A high correlation was found between the free water reabsorption and solute clearance (P < 0.001) in children with nocturnal enuresis. Changes in kidney function in nocturnal enuresis appear to be due to a decrease in the water and ion reabsorption in the thick ascending limb of Henle's loop because of a changed regulation of ion transport in this part of the nephron. Administration of desmopressin or a decrease in prostaglandin production after diclofenac administration restores the ion and water transport in the kidney, which results in the disappearance of nocturnal enuresis. The results indicate a role of changes in regulation of ion transport in renal tubules in the pathogenesis of one of the forms of primary nocturnal enuresis.
Collapse
|
48
|
Natochin YV, Kuznetsova AA. Defect of osmoregulatory renal function in nocturnal enuresis. SCANDINAVIAN JOURNAL OF UROLOGY AND NEPHROLOGY. SUPPLEMENTUM 1999; 202:40-3; discussion 43-4. [PMID: 10573791 DOI: 10.1080/00365599950510184] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/16/2022]
Abstract
Renal function was studied in 62 children with primary nocturnal enuresis (PNE) and in 20 healthy children aged 6-15 years. During the night, children with PNE exhibited an increase in diuresis, free water reabsorption and solute excretion (including sodium and magnesium) in comparison to controls. Intranasal administration of Adiuretin-SD (10.5-24.5 micrograms) in the evening reduced diuresis and ion excretion to normal levels. During the treatment, 61% of the children became completely dry and, in 24% of the children, the number of wet nights was reduced by 50%. It is suggested that in the pathogenesis of PNE, the decrease in ion reabsorption in the thick ascending Henle's loop--resulting in a greater load of tubular fluid in the collecting ducts, an elevation of diuresis and increases in free water reabsorption and solute excretion--plays the leading role in disturbing renal function. Treatment of PNE with desmopressin is pathogenically justified, as it eliminates the principal defect of renal tubular function.
Collapse
|
49
|
Kuznetsova AA, Natochin YV, Papayan AV. Osmoregulatory function of the kidney in enuretic children. SCANDINAVIAN JOURNAL OF UROLOGY AND NEPHROLOGY 1998; 32:132-7. [PMID: 9606787 DOI: 10.1080/003655998750014521] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Twenty children with primary nocturnal enuresis and 20 healthy children of the same age and sex were studied. Natural urination was used for the 24-h urine collection. It was found that urine osmolality and free water reabsorption during the night did not differ statistically significantly between the enuretic children and the healthy. The increased diuresis in the enuretic children was caused by a higher excretion of the osmotically active solutes, including sodium. Use of desmopressin reduced diuresis and natriuresis to normal levels. It is suggested that the main role in the pathogenesis of the studied form of nocturnal enuresis is played by a decrease in ion reabsorption, probably in the thick ascending Henle loop, which facilitates the increase in diuresis and occurrence of nocturnal enuresis.
Collapse
|
50
|
Natochin IV, Kuznetsova AA. [Nocturnal enuresis as a manifestation of autocoidosis]. TERAPEVT ARKH 1998; 69:67-72. [PMID: 9503541] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The study entered 30 children with nocturnal enuresis and 20 healthy controls aged 6-15 years. The enuretic children had a higher night diuresis and free water reabsorption; there was an increase in nocturnal excretion of sodium, calcium and magnesium ions. Before going to bed the patients received diclofenac-sodium. Inhibition of cyclooxygenase and decrease of prostaglandin production led to normalization of diuresis and natriuresis, elimination of nocturnal enuresis episodes. The evidence has been obtained that nocturnal enuresis is accompanied by an increased production of autocoids in the thick ascending Henle loop and, as a result, of an increase in saluresis and diuresis. It is suggested that there is a form of nocturnal diuresis which depends on a local hyperproduction of autocoids. The problem of autocoids role in the internal medicine is discussed.
Collapse
|