Library

X
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
Filter
  • Organic osmolytes  (4)
  • In situ hybridization  (3)
  • Diuresis  (2)
  • 1
    Electronic Resource
    Electronic Resource
    Regulation and localization of organic osmolytes in mammalian kidney (1990)
    Springer
    Journal of molecular medicine 68 (1990), S. 1091-1095 
    Details
    ISSN: 1432-1440
    Keywords: Organic osmolytes ; Rat kidney ; Diabetes insipidus ; Diabetes mellitus ; Hormone treatment
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Four organic small molecules belonging to the chemical groups of trimethylamines (betaine and glycerophosphorylcholine) and polyols (sorbitol and inositol) have been shown to act as organic osmolytes in the kidney. When measured along the corticopapillary axis, each exhibits a specific distribution pattern, indicating a specific localization and function. Studying their behaviour under vasopressin treatment in diabetes insipidus rats and after insulin treatment in diabetes mellitus rats confirmed this conclusion: AVP led to a steady increase of sorbitol and glycerophosphorylcholine over 7 days with no effect on inositol levels. Insulin treatment of diabetic rats, on the other hand, decreased sorbitol with a concomitant increase in glycerophosphorylcholine, again without any effect on tubular inositol concentrations. From this and in vitro studies it can be concluded that both hormones act by indirect mechanisms which alter interstitial osmolality. This in turn leads to a change in tubular osmolyte synthesis, uptake and release rates. In addition, the concentrations of the respective precursors glucose and choline influence the formation rates of sorbitol and betaine.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01798058
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Cellular osmoregulation in the renal papilla (1988)
    Springer
    Journal of molecular medicine 66 (1988), S. 843-848 
    Details
    ISSN: 1432-1440
    Keywords: Renal papillary cells ; Cell electrolytes ; Osmoadaptation ; Organic osmolytes ; Electron microprobe analysis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The cells of the renal papilla are subject to extreme variations in extracellular tonicity. To obtain more insight into the mechanisms whereby these cells adapt osmotically to these unique environmental conditions, elements were measured in individual cells of the rat renal papilla in antidiuresis and after prolonged furosemide administration. In antidiuresis cell sodium, chloride and potassium concentrations did not differ fundamentally from those observed in tubule cells exposed to isotonic surroundings such as in proximal tubule cells. The marked fall in extracellular electrolyte concentrations induced by furosemide was paralleled by a far less pronounced decline in intracellular sodium, chloride and potassium concentrations. These data indicate that papillary cells achieve osmoadaptation to widely differing extracellular tonicities mainly by varying the intracellular concentrations of osmotically active substances other than inorganic electrolytes. Since high concentrations of organic osmolytes (sorbitol, inositol, glycerophosphorylcholine and other trimethylamines) have been detected in the papilla and since the tissue contents of these compounds have been shown to vary in parallel with urine osmolality, it may be concluded that metabolically inert, organic osmolytes play a dominant role in the osmoregulation of renal papillary cells.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01728945
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Cellular response to osmotic stress in the renal medulla (1998)
    Springer
    Pflügers Archiv 436 (1998), S. 814-827 
    Details
    ISSN: 1432-2013
    Keywords: Key words Antidiuresis ; Diuresis ; Heat shock proteins ; Ionic strength ; Organic osmolytes ; Osmotic stress ; Renal medulla
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract  Cells of the renal medulla, which are exposed under normal physiological conditions to widely fluctuating extracellular solute concentrations, respond to hypertonic stress by accumulating the organic osmolytes glycerophosphorylcholine (GPC), betaine, myo-inositol, sorbitol and free amino acids. Increased intracellular contents of these osmolytes are achieved by a combination of increased uptake (myo-inositol and betaine) and synthesis (sorbitol, possibly GPC), decreased degradation (GPC) and reduced osmolyte release. In the medulla of the concentrating kidney, accumulation of organic osmolytes, which do not perturb cell function even at high concentrations, allows the maintenance of ”normal” intracellular concentrations of inorganic electrolytes. Adaptation to decreasing extracellular solute concentrations, e.g. diuresis, is achieved primarily by activation of pathways allowing the efflux of organic osmolytes, and secondarily by inactivation of production (sorbitol) and uptake (betaine, myo-inositol) and stimulation of degradation (GPC). Apart from modulation of the osmolyte content, osmolality-dependent reorganization of the cytoskeleton and expression of specific stress proteins (heat shock proteins) may be further, as yet poorly characterized, components of the regulatory systems involved in the adaptation of medullary cells to osmotic stress.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004240050710
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Expression of Na+/Cl–/betaine and Na+/myo-inositol transporters, aldose reductase and sorbitol dehydrogenase in macula densa cells of the kidney (1998)
    Springer
    Pflügers Archiv 436 (1998), S. 807-809 
    Details
    ISSN: 1432-2013
    Keywords: Key words Aldose reductase ; In situ hybridization ; Macula densa ; Na+/Cl ; /betaine cotransporter ; Na+/myo-inositol cotransporter ; Osmolytes ; Sorbitol dehydrogenase
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract  It has been suggested that macula densa cells may be exposed to hyperosmotic stress. Since chronic exposure to hypertonic stress causes the amount of intracellular organic osmolytes to increase, the expression of transporters and enzymes that participate in the intracellular accumulation of organic osmolytes was examined using non-radioactive in situ hybridization in the macula densa region of control rats and furosemide-treated animals. Both the sodium- and chloride-dependent betaine transporter (BGT) and sodium-dependent myo-inositol transporter (SMIT) were expressed preferentially in macula densa cells and for both mRNAs the signal intensity was visibly reduced by furosemide. The enzymes aldose reductase (which mediates the conversion of glucose to sorbitol) and sorbitol dehydrogenase (which converts sorbitol into fructose) were expressed not only in macula densa cells but also in the surrounding tubular cells, and the expression was insensitive to furosemide. Thus it remains unclear whether the expression of BGT and SMIT is related to a putative hypertonic juxtaglomerular region.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004240050707
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Pretreatment with hypertonic NaCl protects MDCK cells against high urea concentrations (1998)
    Springer
    Pflügers Archiv 435 (1998), S. 407-414 
    Details
    ISSN: 1432-2013
    Keywords: Key words MDCK cells ; Hypertonic stress ; NaCl ; Urea ; Organic osmolytes ; Heat shock proteins ; Cell viability
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract  In antidiuresis, the cells of the renal medulla are exposed to high extracellular concentrations of NaCl and urea. Since urea equilibrates with the intracellular compartment and is known to perturb intracellular macromolecules, high urea concentrations may well disturb the structure and function of cell proteins. Two types of organic substances are believed to counteract the adverse effects of high intracellular urea concentrations: specific organic osmolytes of the trimethylamine family [betaine and glycerophosphorylcholine (GPC)], which accumulate in renal medullary cells during prolonged periods of antidiuresis and cytoprotective heat shock proteins (HSPs), the tissue content of two of which (HSPs 27 and 72) is much higher in the inner medulla than in the iso-osmotic renal cortex. To evaluate the contribution of trimethylamines and HSPs to cytoprotection in the presence of high urea concentrations, the effect of HSP induction and osmolyte accumulation prior to exposure to high urea concentrations was examined in Madin-Darby canine kidney (MDCK) cells. Accumulation of organic osmolytes and synthesis of HSP27 and HSP72 was initiated by hypertonic stress (increasing the osmolality of the medium from 290 to 600 mosmol/kg H2O by NaCl addition). Control, non-conditioned cells remained in the isotonic medium for the same period. Upon subsequent exposure to an additional 600 mM urea in the medium for 24 h, 90% of the osmotically conditioned cells but only 15% of non-conditioned cells survived. The HSP72 and trimethylamine contents of the NaCl-conditioned MDCK cells, but not HSP27 content, correlated positively with cell survival. To separate the effects of organic osmolytes and HSP72, chronically NaCl-adapted MDCK cells were returned to isotonic medium for 1 or 2 days, so depleting them of trimethylamine osmolytes. HSP72, with its longer half life, remained elevated. Subsequent exposure of these cells to 600 mM urea in the medium resulted in about 80% survival. These results suggest that in MDCK cells and probably in the renal medulla, HSP72 and perhaps additional protective factors contribute substantially to the resistance against high urea concentrations.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004240050531
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    Expression of aldose reductase, sorbitol dehydrogenase and Na+/myo-inositol and Na+/Cl–/betaine transporter mRNAs in individual cells of the kidney during changes in the diuretic state (1999)
    Springer
    Pflügers Archiv 437 (1999), S. 248-254 
    Details
    ISSN: 1432-2013
    Keywords: Key words Aldose reductase (AR) ; Antidiuresis ; Diuresis ; Na+/Cl-/betaine cotransporter (BGT) ; Na+/myo-inositol cotransporter (SMIT) ; Non-radioactive in situ hybridization ; Osmoregulation ; Sorbitol dehydrogenase (SDH)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract  The effect of changes in medullary extracellular tonicity on mRNA expression for aldose reductase (AR), sorbitol dehydrogenase (SDH), Na+/Cl–/betaine (BGT) and Na+/myo-inositol (SMIT) cotransporter in different kidney zones was studied using Northern blot analysis and non-radioactive in situ hybridization in four groups of rats: controls, acute diuresis (the loop diuretic furosemide was administered), chronic diuresis (5 days of diuresis), and antidiuresis [5 days of diuresis followed by 24 h deamino-Cys1,d-Arg8 vasopressin (dDAVP)]. Acute administration of the loop diuretic furosemide significantly reduced AR, SMIT and BGT gene expression in the inner and outer medulla compared with controls. Administration of dDAVP to chronically diuretic rats raised the expression of these three mRNAs in the inner but not the outer medulla compared with the chronically diuretic rats. None of these alterations in medullary tonicity significantly changed SDH expression. The in situ hybridization studies showed AR, BGT and SMIT mRNAs to be expressed in both epithelial and non-epithelial cells of the outer and inner medulla. The various cell types (epithelial, endothelial and interstitial cells) differed in their expression pattern and intensity of AR, SDH, BGT and SMIT mRNA, but the inner medullary cells responded uniformly to a decrease in extracellular tonicity with a reduction, and to an increase with enhancement of their AR, BGT and SMIT expression.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004240050776
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    The expression of the gene coding for parathyroid hormone-related protein (PTHrP) during tooth development in the rat (1995)
    Springer
    Cell & tissue research 280 (1995), S. 283-290 
    Details
    ISSN: 1432-0878
    Keywords: Key words: Parathyroid hormone-related protein (PTHrP) ; Teeth ; In situ hybridization ; Rat (Sprague Dawley)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract. By means of in situ hybridisation studies, it is shown that parathyroid hormone-related protein (PTHrP) mRNA is strongly expressed in the developing enamel organs of rat teeth. In particular, the cervical loop hybridises strongly with the PTHrP probe and expression is maintained at this site throughout life in the permanently erupting incisor teeth. In mature molar teeth, expression is downregulated to low levels and confined to the epithelial cell rests of Malassez and/or cementoblasts which may derive from these. The gene is also expressed at low levels in the tissue overlying the erupting molars and, thereafter, in the junctional epithelia and connective tissue cells of the epithelial attachment on all tooth surfaces. The premise that PTHrP may undergo post-translational processing and that the resultant products could act in different ways raises the possibility of its exerting multiple paracrine actions during tooth development. These could include the control of cell division and local vascular dilation during development.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00307800
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    The expression of the gene coding for parathyroid hormone-related protein (PTHrP) during tooth development in the rat (1995)
    Springer
    Cell & tissue research 280 (1995), S. 283-290 
    Details
    ISSN: 1432-0878
    Keywords: Parathyroid hormone-related protein (PTHrP) ; Teeth ; In situ hybridization ; Rat (Sprague Dawley)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract By means of in situ hybridisation studies, it is shown that parathyroid hormone-related protein (PTHrP) mRNA is strongly expressed in the developing enamel organs of rat teeth. In particular, the cervical loop hybridises strongly with the PTHrP probe and expression is maintained at this site throughout life in the permanently erupting incisor teeth. In mature molar teeth, expression is downregulated to low levels and confined to the epithelial cell rests of Malassez and/or cementoblasts which may derive from these. The gene is also expressed at low levels in the tissue overlying the erupting molars and, thereafter, in the junctional epithelia and connective tissue cells of the epithelial attachment on all tooth surfaces. The premise that PTHrP may undergo post-translational processing and that the resultant products could act in different ways raises the possibility of its exerting multiple paracrine actions during tooth development. These could include the control of cell division and local vascular dilation during development.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00307800
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...