scholarly journals Aquaporin complex regulating urine concentration

2012 ◽  
Vol 139 (2) ◽  
pp. 66-69
Author(s):  
Yumi Noda
Keyword(s):  
Urine Concentration

THE SOURCES OF AUXIN HORMONE TO GROWTH OF SHOOT PINEAPPLE STEM CUTTING (Ananascomosus.L. Merr.)

2016 ◽  
Vol 1 (1) ◽  
pp. 45-52
Author(s):  
Palupi Puspitorini
Keyword(s):  
Water Concentration ◽  
Urine Concentration ◽  
Experimental Results ◽  
Stem Cuttings ◽  
Randomized Design ◽  
Natural Hormone ◽  
Cow Urine ◽  
Urine Concentrations ◽  
Completely Randomized Design ◽  
Better Than

The aim of this study was to select the best sources of auxin of which it can stimulate the growth of shoots Pineapple plant cuttings. This research is compiled in a completely randomized design (CRD) with 4 treatments and 6 replications. The Data were statistically Analyzed by the DMRT. Level of treatment given proves that no treatment 0%, cow urine concentration of 25%, young coconut water concentration of 25% and Rootone F 100 mg / cuttings. The results showed that cow urine concentrations of 25% and Rootone F 100 mg give the best results in stimulating the growth of shoots pineapple stem cuttings. Experimental results concluded that the effect of this natural hormone were better than the shoots without given hormone.           

Quali alterazioni dell’esame urine possono preludere ad un interessamento renale della malattia di Fabry

2019 ◽  
Vol 31 (2) ◽  
pp. 137-139
Author(s):  
Sandro Feriozzi ◽  
Mario Mangeri
Keyword(s):  
Clinical Outcome ◽  
Fabry Disease ◽  
Renal Involvement ◽  
Urine Concentration ◽  
Clear Correlation ◽  
Early Indicator ◽  
Cellular Inclusions ◽  
Laboratory Assay

The markers of renal involvement in Anderson-Fabry disease are defects of urine concentration, presence of cells with lipid cytoplasmatic inclusions (mulberry bodies) and podocyturia. The loss of urine concentrating capacity is not easy to detect and the search for cellular inclusions is a complex technique. Moreover, none of the markers has any clear correlation with the stage of the disease. The occurrence of podocytes in the urine (podocyturia) correlates with both renal involvement and clinical outcome; therefore, podocyturia seems to be a promising early indicator of nephropathy. However, a common agreement on the laboratory assay used to measure is still needed.

Sodium Regulation in the Amphipod Gammarus Duebeni Lilljeborg form Freshwater Localities in Ireland

1968 ◽  
Vol 48 (2) ◽  
pp. 339-358
Author(s):  
D. W. SUTCLIFFE ◽  
J. SHAW
Keyword(s):  
Fresh Water ◽  
Loss Rate ◽  
Sea Water ◽  
Detailed Comparison ◽  
Urine Concentration ◽  
Sodium Influx ◽  
Fresh Waters ◽  
Low Sodium ◽  
Characteristic Features ◽  
Sodium Regulation

1. A quantitative study of sodium influx and loss was made on populations of Gammarus duebeni obtained from four freshwater localities in Ireland. 2. Characteristic features of sodium regulation in animals from the four localities were as follows, (a) The sodium influx increases gradually with increasing external sodium concentrations, but a maximum (saturation) level is abruptly reached at an external concentration of 1-2 mM/l. and the transporting system is half saturated at about 0.5 mM/l. sodium, (b) Over the range of sodium concentrations found in fresh waters a low rate of sodium uptake is sufficient to balance sodium losses at concentrations down to between 0.5 and 0.25 mM/l. At lower concentrations the influx is increased and the loss rate is reduced. (c) Calculations suggest that hypotonic urine containing approximately 40 mM/l sodium is produced at external concentrations ranging from fresh water to 40 % sea water. At external concentrations below 0.25 mM/l. sodium the urine concentration is probably reduced to well below 40 mM/l. sodium. 3. A detailed comparison is made of sodium regulation at external concentrations ranging between 0.07 and 1 mM/l. sodium in G. duebeni from fresh water in Ireland and from fresh water and brackish water in Britain. It is suggested that G. duebeni in Ireland constitutes a distinct physiological race adapted for living in fresh waters with relatively low sodium concentrations.

scholarly journals Demonstration of the functional impact of vasopressin signaling in the thick ascending limb by a targeted transgenic rat approach

2016 ◽  
Vol 311 (2) ◽  
pp. F411-F423 ◽  
Author(s):  
Kerim Mutig ◽  
Tordis Borowski ◽  
Christin Boldt ◽  
Aljona Borschewski ◽  
Alexander Paliege ◽  
...  
Keyword(s):  
Epithelial Transport ◽  
Collecting Duct ◽  
Surface Expression ◽  
Urine Concentration ◽  
Dominant Negative ◽  
Transgenic Rat ◽  
Thick Ascending Limb ◽  
Water Reabsorption ◽  
Mediated Effects ◽  
Response To Water

The antidiuretic hormone vasopressin (AVP) regulates renal salt and water reabsorption along the distal nephron and collecting duct system. These effects are mediated by vasopressin 2 receptors (V2R) and release of intracellular Gs-mediated cAMP to activate epithelial transport proteins. Inactivating mutations in the V2R gene lead to the X-linked form of nephrogenic diabetes insipidus (NDI), which has chiefly been related with impaired aquaporin 2-mediated water reabsorption in the collecting ducts. Previous work also suggested the AVP-V2R-mediated activation of Na+-K+-2Cl−-cotransporters (NKCC2) along the thick ascending limb (TAL) in the context of urine concentration, but its individual contribution to NDI or, more generally, to overall renal function was unclear. We hypothesized that V2R-mediated effects in TAL essentially determine its reabsorptive function. To test this, we reevaluated V2R expression. Basolateral membranes of medullary and cortical TAL were clearly stained, whereas cells of the macula densa were unreactive. A dominant-negative, NDI-causing truncated V2R mutant (Ni3-Glu242stop) was then introduced into the rat genome under control of the Tamm-Horsfall protein promoter to cause a tissue-specific AVP-signaling defect exclusively in TAL. Resulting Ni3-V2R transgenic rats revealed decreased basolateral but increased intracellular V2R signal in TAL epithelia, suggesting impaired trafficking of the receptor. Rats displayed significant baseline polyuria, failure to concentrate the urine in response to water deprivation, and hypercalciuria. NKCC2 abundance, phosphorylation, and surface expression were markedly decreased. In summary, these data indicate that suppression of AVP-V2R signaling in TAL causes major impairment in renal fluid and electrolyte handling. Our results may have clinical implications.

Impairment of osmotically stimulated AVP release in patients with primary polydipsia

1993 ◽  
Vol 265 (6) ◽  
pp. R1247-R1252 ◽  
Author(s):  
A. M. Moses ◽  
B. Clayton
Keyword(s):  
Diabetes Insipidus ◽  
Arginine Vasopressin ◽  
Plasma Osmolality ◽  
Normal Subjects ◽  
Urine Concentration ◽  
Published Data ◽  
Posterior Pituitary ◽  
Primary Polydipsia ◽  
Number Of Factors

The secretion of arginine vasopressin (AVP) from the posterior pituitary is primarily and finely regulated by the osmolality of plasma. Even though a number of factors alter osmolality-induced release of AVP, there are no published data in humans that have addressed the role of chronic overhydration on this phenomenon. To address this problem we have identified eight patients with primary polydipsia using criteria not involving measurement of AVP, and have subjected them to standardized infusions of hypertonic saline. These patients had less AVP in both plasma and urine in relation to plasma osmolality than was found in normal subjects. In addition, their rate of rise of plasma and urine AVP was less than in normal subjects. Their osmotic threshold for AVP release may have been higher than normal. These data demonstrate that chronic overhydration in humans downregulates the release of AVP in response to hypertonicity. This phenomenon may explain the impairment of urine concentration in patients with primary polydipsia and emphasizes the basis of the difficulty that may occur clinically in differentiating between patients with primary polydipsia and partial central diabetes insipidus.

scholarly journals The Significance of Urinary Markers in the Evaluation of Diabetic Nephropathy

2008 ◽  
Vol 27 (3) ◽  
pp. 376-382 ◽  
Author(s):  
Tatjana Cvetković ◽  
Predrag Vlahović ◽  
Vidosava đorđević ◽  
Lilika Zvezdanović ◽  
Dušica Pavlović ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Diabetes Mellitus ◽  
Diabetic Nephropathy ◽  
Urine Concentration ◽  
Control Group ◽  
Diabetic Patients ◽  
Type 2 Diabetic Patients ◽  
Urinary Markers ◽  
Stress Markers

The Significance of Urinary Markers in the Evaluation of Diabetic Nephropathy Oxidative stress is considered to be a unifying link between diabetes mellitus (DM) and its complications, including nephropathy (DN). The aim of this study was to determine the parameters of oxidative injury of lipids and proteins as well as the activity of ectoenzymes in the urine of DN patients. The study included 40 individuals: 10 patients with type 2 diabetes mellitus and microalbuminuria (DMT2-MIA), 10 type 2 diabetic patients with macroalbuminuria (DMT2-MAA), 10 patients with type 1 diabetes and microalbuminuria (DMT1-MIA) and 10 age- and sex-matched healthy subjects (control). In the urine we determined TBA reactive substances (TBARS), reactive carbonyl groups (RCG), and the activity of ectoenzymes N-acetyl-β-d-glucosaminidase (NAG), plasma cell differentiation antigen (PC-1), aminopeptidase N (APN) and dipeptidyl peptidase IV (DPP IV). A higher concentration of TBARS in the urine was found in DMT2-MIA and DMT1-MIA, compared to the control group (p<0.001 and P<0.05). The urine concentration of RCD shows similar results with a significant elevation in the groups with DMT2-MAA and DMT1-MIA, compared to the DMT2-MIA (p<0.001) and control group (p<0.001). Activities of NAG, APN and DPPIV were significantly higher in the urine of DMT2-MAA, compared to the control (p<0.01). The activity of PC-1 was slightly increased in that group, but not significantly. In conclusion, the level of oxidative stress markers and activities of brush border ectoenzymes in the urine may be a useful non-invasive and easily repeatable test in DN.

Acute Effect of Parathyroid Hormone on Urine Concentration in the Rat

1995 ◽  
Vol 88 (2) ◽  
pp. 197-201 ◽  
Author(s):  
S. L. Carney ◽  
A. H. B. Gillies
Keyword(s):  
Parathyroid Hormone ◽  
Arginine Vasopressin ◽  
Partial Agonist ◽  
Acute Effect ◽  
Inhibitory Effect ◽  
Urine Concentration ◽  
Antidiuretic Effect ◽  
Plasma Calcium Concentration ◽  
Subsequent Effect

1. It has been demonstrated that parathyroid hormone can increase adenylate cyclase activity in the rat papilla, produce a small antidiuretic effect and in vitro can interfere with the action of arginine vasopressin on water transport. Clearance studies were performed in the anaesthetized water diuretic thyroparathyroidectomized rat to evaluate further the effect of parathyroid hormone on urine concentration in the presence and absence of arginine vasopressin. 2. A maximal phosphaturic concentration of rat parathyroid hormone (2 μg/kg) reduced urine flow from 125 ± 7 to 81 ± 9 μl/min within 10 min (P < 0.01). Addition of a maximal antidiuretic concentration of arginine vasopressin (100 ng/kg) produced a delayed and diminished antidiuretic response when compared with a group of rats not pretreated with parathyroid hormone (47 ± 5 compared with 27 ± 5 μl/min; P < 0.01). However, a supramaximal arginine vasopressin concentration (1000 ng/kg) produced a maximal antidiuretic effect in the presence of parathyroid hormone. 3. To evaluate further the inhibitory effect of parathyroid hormone on arginine vasopressin-induced anti-diuresis, parathyroid hormone (2 μg/kg) was administered to one group of rats and a minimally effective arginine vasopressin concentration (7.5 ng/kg) to another group, which produced a similar antidiuretic effect. However, the subsequent effect of a maximal antidiuretic arginine vasopressin concentration (100 ng/kg) was again significantly blunted in the group pretreated with parathyroid hormone. 4. Parathyroid hormone produced only a small increase in mean plasma calcium concentration, and glomerular filtration rate was not altered by either hormone. 5. These results demonstrate that high physiological concentrations of parathyroid hormone do have a significant antidiuretic effect and can interfere with the action of arginine vasopressin. This suggests that parathyroid hormone may act as a partial agonist to arginine vasopressin in the collecting system.

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