Food restriction prevents age-related polyuria by vasopressin-dependent recruitment of aquaporin-2

2001 ◽  
Vol 281 (6) ◽  
pp. F1123-F1131 ◽  
Author(s):  
S. Combet ◽  
L. Teillet ◽  
G. Geelen ◽  
B. Pitrat ◽  
R. Gobin ◽  
...  

First published August 8, 2001; 10.1152/ajprenal.00139.2001.—The mechanisms underlying the prevention of age-related polyuria by chronic food restriction were investigated in female WAG/Rij rats. The decreased osmolality of renal papilla observed in senescent rats was not corrected by food restriction. A reduced urea content in the inner medulla of senescent rats, fed ad libitum or food-restricted, was suggested by the marked decrease in expression of UT-A1 and UT-B1 urea transporters. Aquaporin-2 (AQP2) downregulation in the inner medulla of senescent rats was partially prevented by food restriction. Both AQP2 and the phosphorylated form of AQP2 (p-AQP2), the presence of which was diffuse within the cytoplasm of collecting duct principal cells in normally fed senescent rats, were preferentially targeted at the apical region of the cells in food-restricted senescent animals. Plasma vasopressin (AVP) was similar in 10- and 30-mo-old rats fed ad libitum, but was doubled in food-restricted 30-mo-old rats. This study indicates that 1) kidney aging is associated with a marked decrease in AQP2, UT-A1, and UT-B1 expression in the inner medulla and a reduced papillary osmolality; and 2) the prevention of age-related polyuria by chronic food restriction occurs through an improved recruitment of AQP2 and p-AQP2 to the apical membrane in inner medulla principal cells, permitted by increased plasma AVP concentration.

2000 ◽  
Vol 11 (8) ◽  
pp. 1488-1497
Author(s):  
LAURENT TEILLET ◽  
PHILIPPE VERBEKE ◽  
SABINE GOURAUD ◽  
HILAIRE BAKALA ◽  
CAROLINE BOROT-LALOI ◽  
...  

Abstract.Tissue content of advanced glycation end products (AGE) increases with age and contributes to the changes in structure and function of the renal and cardiovascular systems. The effect of chronic food restriction on this AGE accumulation was investigated in lean WAG/Rij rats. A 30% food restriction performed from 10 to 30 mo in female rats reduced their mean body weight from 240 ± 7 to 160 ± 12 g, but did not modify their survival. AGE collagen content increased from 14.3 ± 5.5 to 104.7 ± 13.0 arbitrary units per microgram (AU/μg) of hydroxyproline (OHPro) in kidney between 10 and 30 mo, and from 9.7 ± 1.2 to 310.6 ± 34.6 AU/μg OHPro in the abdominal aorta. Food restriction reduced AGE accumulation to 21.4 ± 3.3 and 74.6 ± 16.5 AU/μg OHPro in kidney and aorta of 30-mo-old animals. Similar results were found for collagen prepared from isolated glomeruli (7.8 ± 1.2, 81.2 ± 16.1, and 10.3 ± 4.3 AU/μg OHPro in 10-mo, 30-mo, and restricted 30-mo-old rats). Reduction of intrarenal and arterial AGE accumulation by food restriction was confirmed by immunostaining in optical microscopy. Age-related changes in arterial and kidney structures as polyuria and proteinuria were mainly prevented by food restriction. These data indicate that chronic food restriction reduces the accumulation of AGE and preserves the structure and function of the renal and cardiovascular systems in learn rats, although it did not affect survival of the animals between 10 and 30 mo.


1994 ◽  
Vol 77 (1) ◽  
pp. 160-164 ◽  
Author(s):  
A. D. Mooradian ◽  
M. P. Habib ◽  
F. Dickerson ◽  
T. Yetskievych

The effect of age on thyroid hormone-induced lipid peroxidation in rats was determined by measuring ethane exhalation (EE) rate. The mean basal EE rates (in pmol.min-1 x 100 g-1) at room air in 25-mo-old aged rats [3.07 +/- 0.26 (SE)] and in intermediate age (18-mo-old) rats (3.42 +/- 0.18) were significantly lower than that in young (3- to 5-mo-old) rats (4.44 +/- 0.27) (P < 0.01). After 8 days of L-3,5,3′-triiodothyronine (T3) administration, EE rates in aged rats (4.10 +/- 0.25) and in intermediate-age rats (4.16 +/- 0.35) were significantly lower than that in young rats (5.61 +/- 0.36) (P < 0.01). T3-treated young rats pair-fed with aged rats for 2 wk had EE rates (5.53 +/- 0.18) comparable to ad libitum-fed young rats, although the basal rate of EE was significantly reduced with partial food restriction (4.44 +/- 0.27 vs. 3.50 +/- 0.24) (P < 0.01). These observations indicate that reduced food intake with age cannot account for the age-related changes in T3-stimulated peroxidation rate of lipids.


2003 ◽  
Vol 121 (5) ◽  
pp. 413-425 ◽  
Author(s):  
Warren G. Hill ◽  
Marcia A. Kaetzel ◽  
Bellamkonda K. Kishore ◽  
John R. Dedman ◽  
Mark L. Zeidel

Annexin A4 (Anx4) belongs to a ubiquitous family of Ca2+-dependent membrane-binding proteins thought to be involved in membrane trafficking and membrane organization within cells. Anx4 localizes to the apical region in epithelia; however, its physiological role is unclear. We show that Anx4 exhibited binding to liposomes (phosphatidylcholine:phosphatidylserine, 1:1) in the presence of Ca2+ and binding was reversible with EDTA. Anx4 binding resulted in liposome aggregation and a reduction in membrane water permeability of 29% (P &lt; 0.001) at 25°C. These effects were not seen in the presence of Ca2+ or Anx4 alone and were reversible with EDTA. Measurements of membrane fluidity made by monitoring fluorescence anisotropy of 2-(12-(7-nitrobenz-2-oxa-1,3-diazol-4-yl)amino)dodecanoyl-1-hexadecanoyl-sn-glycero-3-phosphocholine (NBD-HPC) demonstrated that Anx4 binding rigidified the outer leaflet of the bilayer (P &lt; 0.001), thus providing a molecular explanation for the inhibition of water flux. To determine whether Anx4 would produce similar effects on physiological membranes we constructed liposomes which recapitulated the lipid composition of the inner leaflet of the MDCK apical membrane. These membranes exhibited reductions to water permeability upon Anx4 binding (19.5% at 25°C, 31% at 37°C; P &lt; 0.01 and P &lt; 0.001, respectively) and to proton permeability (15% at 25°C, 19.5% at 37°C; P &lt; 0.05). Since our in vitro experiments indicated an effect on membrane permeability, we examined localization of Anx4 in the kidney collecting duct, a region of the nephron responsible for concentrating urine through water reabsorbtion. Anx4 was shown to colocalize apically with aquaporin 2 (AQP2) in collecting duct epithelia. To test for the existence of a functional interaction between Anx4 and AQP2 we isolated AQP2-containing endosomes and exposed them to Anx4/Ca2+. Water flux rates were unchanged, indicating Anx4 does not directly regulate AQP2. We conclude that Anx4 can alter the physical properties of membranes by associating with them and regulate passive membrane permeability to water and protons. These properties represent important new functions for Anx4.


2000 ◽  
Vol 279 (1) ◽  
pp. F144-F152 ◽  
Author(s):  
L. Preisser ◽  
L. Teillet ◽  
S. Aliotti ◽  
R. Gobin ◽  
V. Berthonaud ◽  
...  

The mechanisms underlying age-related polyuria were investigated in 10- and 30-mo-old female WAG/Rij rats. Urinary volume and osmolality were 3.9 ± 0.3 ml/24 h and 2,511 ± 54 mosmol/kgH2O in adult rats and 12.8 ± 0.8 ml/24 h and 1,042 ± 44 mosmol/kgH2O in senescent animals. Vasopressin V2 receptor mRNA did not significantly differ between 10 and 30 mo, and [3H]vasopressin binding sites in membrane papilla were reduced by 30%. The cAMP content of the papilla was unchanged with age, whereas papillary osmolality was significantly lowered in senescent animals. The expression of aquaporin-1 (AQP1) and -4 was mostly unaltered from 10 to 30 mo. In contrast, aquaporin-2 (AQP2) and -3 (AQP3) expression was downregulated by 80 and 50%, respectively, and AQP2 was markedly redistributed into the intracellular compartment, in inner medulla of senescent animals, but not in renal cortex. These results indicate that age-related polyuria is associated with a downregulation of AQP2 and AQP3 expression in the medullary collecting duct, which is independent of vasopressin-mediated cAMP accumulation.


PLoS ONE ◽  
2014 ◽  
Vol 9 (1) ◽  
pp. e87239 ◽  
Author(s):  
Eric Féraille ◽  
Eva Dizin ◽  
Isabelle Roth ◽  
Jean-Paul Derouette ◽  
Ildiko Szanto ◽  
...  

1995 ◽  
Vol 268 (4) ◽  
pp. C952-C957 ◽  
Author(s):  
J. Yannariello-Brown ◽  
S. H. Chapman ◽  
W. F. Ward ◽  
T. C. Pappas ◽  
P. H. Weigel

Circulating hyaluronan (HA) levels were investigated as a function of age and diet in Fischer 344 male rats. A biphasic pattern of age-related changes was observed in rats fed ad libitum a diet in which the protein source was soya/fish meal. HA levels in 3- to 6- and 22- to 29-mo-old rats were not statistically different. However, HA levels in 12- to 20-mo-old rats were 10-29% of the levels in younger or aged adults. HA levels were also measured in rats fed ad libitum a semisynthetic diet in which the protein source was hydrolyzed casein. Whereas the two colonies exhibited similar biphasic age-related changes, HA levels differed 4- to 20-fold at every age examined. Caloric restriction affected HA levels in 19-mo-old casein-fed rats; HA levels were 2.3 times higher than age-matched controls and were not statistically different from young or aged animals. Serum and plasma HA levels were identical in the same individuals at all ages tested. These data suggest that HA turnover and metabolism in the rat are affected by age, dietary composition, and caloric intake.


2009 ◽  
Vol 297 (1) ◽  
pp. F10-F18 ◽  
Author(s):  
Udo Hasler ◽  
Valérie Leroy ◽  
Pierre-Yves Martin ◽  
Eric Féraille

The renal cortico-papillary osmotic gradient is generated by sodium reabsorption in the thick ascending limb. The antidiuretic hormone arginine vasopressin (AVP) increases collecting duct water permeability by enhancing aquaporin-2 (AQP2) water channel insertion in the apical membrane of principal cells, allowing water to passively flow along the osmotic gradient from the tubule lumen to the interstitium. In addition to short-term AQP2 redistribution between intracellular compartments and the cell surface, AQP2 whole cell abundance is tightly regulated. AVP is a major transcriptional activator of the AQP2 gene, and stimulation of insulin- and calcium-sensing receptors respectively potentiate and reduce its action. Extracellular tonicity is another key factor that determines the levels of AQP2 abundance. Its effect is dependent on activation of the tonicity-responsive enhancer binding protein that reinforces AVP-induced AQP2 transcriptional activation. Conversely, activation of the NF-κB transcriptional factor by proinflammatory factors reduces AQP2 gene transcription. Aldosterone additionally regulates AQP2 whole cell abundance by simultaneously reducing AQP2 gene transcription and stimulating AQP2 mRNA translation. These examples illustrate how cross talk between various stimuli regulates AQP2 abundance in collecting duct principal cells and consequently contributes to maintenance of body water homeostasis.


2000 ◽  
Vol 278 (4) ◽  
pp. C791-C802 ◽  
Author(s):  
Anna L. Stevens ◽  
Sylvie Breton ◽  
Corinne E. Gustafson ◽  
Richard Bouley ◽  
Raoul D. Nelson ◽  
...  

Aquaporin 2 (AQP2), the vasopressin-regulated water channel, was originally identified in renal collecting duct principal cells. However, our recent description of AQP2 in the vas deferens indicated that this water channel may have extra-renal functions, possibly related to sperm concentration in the male reproductive tract. In this study, we have examined the regulation and membrane insertion pathway of AQP2 in the vas deferens. The amino acid sequence of vas deferens AQP2 showed 100% identity to the renal protein. AQP2 was highly expressed in the distal portion (ampulla) of the vas deferens, but not in the proximal portion nearest the epididymis. It was concentrated on the apical plasma membrane of vas deferens principal cells, and very little was detected on intracellular vesicles. Protein expression levels and cellular localization patterns were similar in normal rats and vasopressin-deficient Brattleboro homozygous rats, and were not changed after 36 h of dehydration, or after 3 days of vasopressin infusion into Brattleboro rats. AQP2 was not found in apical endosomes (labeled with Texas Red-dextran) in vas deferens principal cells, indicating that it is not rapidly recycling in this tissue. Finally, vasopressin receptors were not detectable on vas deferens epithelial cell membranes using a [3H]vasopressin binding assay. These data indicate that AQP2 is a constitutive apical membrane protein in the vas deferens, and that it is not vasopressin-regulated in this tissue. Thus AQP2 contains targeting information that can be interpreted in a cell-type-specific fashion in vivo.


1997 ◽  
Vol 273 (5) ◽  
pp. H2333-H2342 ◽  
Author(s):  
Simon Klebanov ◽  
Jeremiah T. Herlihy ◽  
Gregory L. Freeman

Food restriction (FR) is the only known intervention capable of increasing mammalian life span. It not only increases longevity, but reduces the incidence of a broad spectrum of age-related pathologies, including cardiomyopathy, and retards the physiological decline associated with aging. Previous work from this laboratory has shown that long-term FR affects the contractile machinery of the heart, shifting the cardiac myosin profile from the fast, V1 isoform to the slow, V3 isoform. The aim of the present study was to determine whether FR also induces changes in cardiac mechanics. Isolated, isovolumically beating hearts were examined from four groups of rats: 1) ad libitum-fed rats killed at 10–13 mo of age, 2) FR rats offered only 60% of the calories consumed by ad libitum-fed rats and killed at the same age, 3) young ad libitum-fed rats having the same heart weights as the FR rats, and 4) ad libitum-fed rats subjected to short-term FR, i.e., for the last 3 wk of life, and also killed at 10–13 mo of age. Both short- and long-term FR profoundly and to approximately the same extent affected cardiac mechanics. Hearts from FR rats developed much higher pressures than hearts from the ad libitum-fed rats under conditions of low-calcium perfusate. This difference disappeared, however, when contractility was enhanced by either calcium or isoproterenol. FR prolonged both contraction and relaxation times. Long-term ad libitum-fed rats (adult, 10–13 mo of age) had a lower isoproterenol sensitivity than the young ad libitum-fed rats (10 wk of age). Both short- and long-term FR restored the sensitivity to isoproterenol. In summary, FR profoundly affects many aspects of cardiac mechanics, enhancing some age-related changes (prolongation of the contraction and relaxation times), attenuating another (increasing the isoproterenol sensitivity), and, finally, inducing some unique changes unrelated to age (increased pressure development under low-calcium perfusate).


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