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Renal response to L-arginine in diabetic rats. A possible link between nitric oxide system and aquaporin-2.

Ortiz MC, Albertoni Borghese MF, Balonga SE, Lavagna A, Filipuzzi AL, Elesgaray R, Costa MA, Majowicz MP - PLoS ONE (2014)

Bottom Line: Western blot was used to detect the expression of AQP2 and NOS types I and III; real time PCR was used to quantify AQP2 mRNA.These results suggest that the decreased NOS activity in collecting ducts of the renal outer medulla may cause, at least in part, the decreased expression of AQP2 in this model of diabetes and constitute additional evidence supporting a role for NO in contributing to renal water reabsorption through the modulation of AQP2 expression in this pathological condition.However, we cannot discard that another pathway different from NOS also exists that links L-Arg to AQP2 expression.

View Article: PubMed Central - PubMed

Affiliation: Cátedra de Biología Celular y Molecular, Departamento de Ciencias Biológicas, Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires. Buenos Aires, Argentina.

ABSTRACT
The aim of this study was to evaluate whether L-Arginine (L-Arg) supplementation modifies nitric oxide (NO) system and consequently aquaporin-2 (AQP2) expression in the renal outer medulla of streptozotocin-diabetic rats at an early time point after induction of diabetes. Male Wistar rats were divided in four groups: Control, Diabetic, Diabetic treated with L-Arginine and Control treated with L-Arginine. Nitric oxide synthase (NOS) activity was estimated by [14C] L-citrulline production in homogenates of the renal outer medulla and by NADPH-diaphorase staining in renal outer medullary tubules. Western blot was used to detect the expression of AQP2 and NOS types I and III; real time PCR was used to quantify AQP2 mRNA. The expression of both NOS isoforms, NOS I and NOS III, was decreased in the renal outer medulla of diabetic rats and L-Arg failed to prevent these decreases. However, L-Arg improved NO production, NADPH-diaphorase activity in collecting ducts and other tubular structures, and NOS activity in renal homogenates from diabetic rats. AQP2 protein and mRNA were decreased in the renal outer medulla of diabetic rats and L-Arg administration prevented these decreases. These results suggest that the decreased NOS activity in collecting ducts of the renal outer medulla may cause, at least in part, the decreased expression of AQP2 in this model of diabetes and constitute additional evidence supporting a role for NO in contributing to renal water reabsorption through the modulation of AQP2 expression in this pathological condition. However, we cannot discard that another pathway different from NOS also exists that links L-Arg to AQP2 expression.

No MeSH data available.


Related in: MedlinePlus

NOS I expression in homogenates of the renal outer medulla.A. Representative western blot analysis of NOS I (155 kDa band) and tubulin (50 kDa band) in the renal outer medulla; B. NOS I expression indicated as NOS I/tubulin ratio fold change from control untreated rats. Two-way ANOVA showed no statistically significant interaction between the effects of Diabetes and L-Arg treatment on NOS I expression. The effect of Diabetes was considered very significant (p<0.01), the effect of L-Arg was not significant. **p<0.01 vs. control untreated rats, ##p<0.01 vs. control rats treated with L-Arg. Data are mean ± SEM (n = 6).
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pone-0104923-g002: NOS I expression in homogenates of the renal outer medulla.A. Representative western blot analysis of NOS I (155 kDa band) and tubulin (50 kDa band) in the renal outer medulla; B. NOS I expression indicated as NOS I/tubulin ratio fold change from control untreated rats. Two-way ANOVA showed no statistically significant interaction between the effects of Diabetes and L-Arg treatment on NOS I expression. The effect of Diabetes was considered very significant (p<0.01), the effect of L-Arg was not significant. **p<0.01 vs. control untreated rats, ##p<0.01 vs. control rats treated with L-Arg. Data are mean ± SEM (n = 6).

Mentions: Figure 2 and 3 show that the expression of both NOS I and NOS III was decreased in the renal outer medulla of diabetic untreated rats. This result may explain, at least in part, the decreased NADPH-d activity in most renal tubules and the decreased NOS activity measured as [14C] L-citrulline production in the diabetic rats. On the other hand, L-Arg administration to diabetic rats did not prevent the decreased expression of NOS I and NOS III (Fig. 2 and 3).


Renal response to L-arginine in diabetic rats. A possible link between nitric oxide system and aquaporin-2.

Ortiz MC, Albertoni Borghese MF, Balonga SE, Lavagna A, Filipuzzi AL, Elesgaray R, Costa MA, Majowicz MP - PLoS ONE (2014)

NOS I expression in homogenates of the renal outer medulla.A. Representative western blot analysis of NOS I (155 kDa band) and tubulin (50 kDa band) in the renal outer medulla; B. NOS I expression indicated as NOS I/tubulin ratio fold change from control untreated rats. Two-way ANOVA showed no statistically significant interaction between the effects of Diabetes and L-Arg treatment on NOS I expression. The effect of Diabetes was considered very significant (p<0.01), the effect of L-Arg was not significant. **p<0.01 vs. control untreated rats, ##p<0.01 vs. control rats treated with L-Arg. Data are mean ± SEM (n = 6).
© Copyright Policy
Related In: Results  -  Collection

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Show All Figures
getmorefigures.php?uid=PMC4128736&req=5

pone-0104923-g002: NOS I expression in homogenates of the renal outer medulla.A. Representative western blot analysis of NOS I (155 kDa band) and tubulin (50 kDa band) in the renal outer medulla; B. NOS I expression indicated as NOS I/tubulin ratio fold change from control untreated rats. Two-way ANOVA showed no statistically significant interaction between the effects of Diabetes and L-Arg treatment on NOS I expression. The effect of Diabetes was considered very significant (p<0.01), the effect of L-Arg was not significant. **p<0.01 vs. control untreated rats, ##p<0.01 vs. control rats treated with L-Arg. Data are mean ± SEM (n = 6).
Mentions: Figure 2 and 3 show that the expression of both NOS I and NOS III was decreased in the renal outer medulla of diabetic untreated rats. This result may explain, at least in part, the decreased NADPH-d activity in most renal tubules and the decreased NOS activity measured as [14C] L-citrulline production in the diabetic rats. On the other hand, L-Arg administration to diabetic rats did not prevent the decreased expression of NOS I and NOS III (Fig. 2 and 3).

Bottom Line: Western blot was used to detect the expression of AQP2 and NOS types I and III; real time PCR was used to quantify AQP2 mRNA.These results suggest that the decreased NOS activity in collecting ducts of the renal outer medulla may cause, at least in part, the decreased expression of AQP2 in this model of diabetes and constitute additional evidence supporting a role for NO in contributing to renal water reabsorption through the modulation of AQP2 expression in this pathological condition.However, we cannot discard that another pathway different from NOS also exists that links L-Arg to AQP2 expression.

View Article: PubMed Central - PubMed

Affiliation: Cátedra de Biología Celular y Molecular, Departamento de Ciencias Biológicas, Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires. Buenos Aires, Argentina.

ABSTRACT
The aim of this study was to evaluate whether L-Arginine (L-Arg) supplementation modifies nitric oxide (NO) system and consequently aquaporin-2 (AQP2) expression in the renal outer medulla of streptozotocin-diabetic rats at an early time point after induction of diabetes. Male Wistar rats were divided in four groups: Control, Diabetic, Diabetic treated with L-Arginine and Control treated with L-Arginine. Nitric oxide synthase (NOS) activity was estimated by [14C] L-citrulline production in homogenates of the renal outer medulla and by NADPH-diaphorase staining in renal outer medullary tubules. Western blot was used to detect the expression of AQP2 and NOS types I and III; real time PCR was used to quantify AQP2 mRNA. The expression of both NOS isoforms, NOS I and NOS III, was decreased in the renal outer medulla of diabetic rats and L-Arg failed to prevent these decreases. However, L-Arg improved NO production, NADPH-diaphorase activity in collecting ducts and other tubular structures, and NOS activity in renal homogenates from diabetic rats. AQP2 protein and mRNA were decreased in the renal outer medulla of diabetic rats and L-Arg administration prevented these decreases. These results suggest that the decreased NOS activity in collecting ducts of the renal outer medulla may cause, at least in part, the decreased expression of AQP2 in this model of diabetes and constitute additional evidence supporting a role for NO in contributing to renal water reabsorption through the modulation of AQP2 expression in this pathological condition. However, we cannot discard that another pathway different from NOS also exists that links L-Arg to AQP2 expression.

No MeSH data available.


Related in: MedlinePlus