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Role of renal nerves in the treatment of renovascular hypertensive rats with L-arginine.

Gouvea SA, Tiradentes RV, Santuzzi CH, Mengal V, Futuro Neto Hde A, Silva NF, Abreu GR - Int J Hypertens (2014)

Bottom Line: Arterial blood pressure, water intake, urine volume, and sodium excretion were measured.L-arg and denervation induced increases in water intake and urine volume, and L-arg caused a significant natriuretic effect.Our results suggest that renal sympathetic activity participates in the genesis and the maintenance of the hypertension and also demonstrate that treatment with L-arg alone is incapable of normalizing the MAP and that the effect of such treatment is not additive with the effect of kidney denervation.

View Article: PubMed Central - PubMed

Affiliation: Department of Physiological Sciences, Health Sciences Center, Federal University of Espírito Santo, Avenida Marechal Campos 1456, 29040-577 Vitória, ES, Brazil.

ABSTRACT
The purpose was to determine the role of renal nerves in mediating the effects of antihypertensive treatment with L-arginine in a renovascular hypertension model. The 2K1C (two-kidney one-clip model) hypertensive rats were submitted to bilateral surgical-pharmacological renal denervation. The animals were subdivided into six experimental groups: normotensive control rats (SHAM), 2K1C rats, 2K1C rats treated with L-arginine (2K1C + L-arg), denervated normotensive (DN) rats, denervated 2K1C (2K1C + DN) rats, and denervated 2K1C + L-arg (2K1C + DN + L-arg) rats. Arterial blood pressure, water intake, urine volume, and sodium excretion were measured. The 2K1C rats exhibited an increase in the mean arterial pressure (MAP) (from 106 ± 3 to 183 ± 5.8 mmHg, P < 0.01), whereas L-arg treatment induced a reduction in the MAP (143 ± 3.4 mmHg) without lowering it to the control level. Renal nerve denervation reduced the MAP to normotensive levels in 2K1C rats with or without chronic L-arg treatment. L-arg and denervation induced increases in water intake and urine volume, and L-arg caused a significant natriuretic effect. Our results suggest that renal sympathetic activity participates in the genesis and the maintenance of the hypertension and also demonstrate that treatment with L-arg alone is incapable of normalizing the MAP and that the effect of such treatment is not additive with the effect of kidney denervation.

No MeSH data available.


Related in: MedlinePlus

Urinary sodium excretion after oral L-arginine (L-arg) administration to the SHAM, two-kidney one-clip, and denervated groups. The groups are as follows: SHAM: normotensive control; 2K1C: two-kidney one-clip; 2K1C + L-arg: two-kidney one-clip treated with L-arginine; DN: denervated normotensive; 2K1C + DN: denervated two-kidney one-clip; and 2K1C + DN + L-arg: denervated two-kidney one-clip treated with L-arginine. The data are shown for 7 days of L-arg administration. Data are reported as the means ± SEM. **P < 0.01 compared with SHAM; ††P < 0.01 compared with DN; †P < 0.05 and ††P < 0.01 compared with 2K1C; #P < 0.05 compared with 2K1C + L-arg; P < 0.05 compared with 2K1C + DN (Tukey test).
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fig3: Urinary sodium excretion after oral L-arginine (L-arg) administration to the SHAM, two-kidney one-clip, and denervated groups. The groups are as follows: SHAM: normotensive control; 2K1C: two-kidney one-clip; 2K1C + L-arg: two-kidney one-clip treated with L-arginine; DN: denervated normotensive; 2K1C + DN: denervated two-kidney one-clip; and 2K1C + DN + L-arg: denervated two-kidney one-clip treated with L-arginine. The data are shown for 7 days of L-arg administration. Data are reported as the means ± SEM. **P < 0.01 compared with SHAM; ††P < 0.01 compared with DN; †P < 0.05 and ††P < 0.01 compared with 2K1C; #P < 0.05 compared with 2K1C + L-arg; P < 0.05 compared with 2K1C + DN (Tukey test).

Mentions: The level of sodium excretion was significantly higher (P < 0.01) in the 2K1C + L-arg group than in the untreated and SHAM groups (1.1 ± 0.05, 0.8 ± 0.05, and 0.72 ± 0.02 mEq/day, resp.). In addition, the treatment associated with denervation (1.4 ± 0.08 mEq/day) further increased the level of sodium excretion relative to that of the other groups (0.94 ± 0.06 mEq/day in the DN group and 0.93 ± 0.06 mEq/day in the 2K1C + DN group) (Figure 3). The levels of potassium excretion were similar in all groups (data not shown).


Role of renal nerves in the treatment of renovascular hypertensive rats with L-arginine.

Gouvea SA, Tiradentes RV, Santuzzi CH, Mengal V, Futuro Neto Hde A, Silva NF, Abreu GR - Int J Hypertens (2014)

Urinary sodium excretion after oral L-arginine (L-arg) administration to the SHAM, two-kidney one-clip, and denervated groups. The groups are as follows: SHAM: normotensive control; 2K1C: two-kidney one-clip; 2K1C + L-arg: two-kidney one-clip treated with L-arginine; DN: denervated normotensive; 2K1C + DN: denervated two-kidney one-clip; and 2K1C + DN + L-arg: denervated two-kidney one-clip treated with L-arginine. The data are shown for 7 days of L-arg administration. Data are reported as the means ± SEM. **P < 0.01 compared with SHAM; ††P < 0.01 compared with DN; †P < 0.05 and ††P < 0.01 compared with 2K1C; #P < 0.05 compared with 2K1C + L-arg; P < 0.05 compared with 2K1C + DN (Tukey test).
© Copyright Policy - open-access
Related In: Results  -  Collection

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fig3: Urinary sodium excretion after oral L-arginine (L-arg) administration to the SHAM, two-kidney one-clip, and denervated groups. The groups are as follows: SHAM: normotensive control; 2K1C: two-kidney one-clip; 2K1C + L-arg: two-kidney one-clip treated with L-arginine; DN: denervated normotensive; 2K1C + DN: denervated two-kidney one-clip; and 2K1C + DN + L-arg: denervated two-kidney one-clip treated with L-arginine. The data are shown for 7 days of L-arg administration. Data are reported as the means ± SEM. **P < 0.01 compared with SHAM; ††P < 0.01 compared with DN; †P < 0.05 and ††P < 0.01 compared with 2K1C; #P < 0.05 compared with 2K1C + L-arg; P < 0.05 compared with 2K1C + DN (Tukey test).
Mentions: The level of sodium excretion was significantly higher (P < 0.01) in the 2K1C + L-arg group than in the untreated and SHAM groups (1.1 ± 0.05, 0.8 ± 0.05, and 0.72 ± 0.02 mEq/day, resp.). In addition, the treatment associated with denervation (1.4 ± 0.08 mEq/day) further increased the level of sodium excretion relative to that of the other groups (0.94 ± 0.06 mEq/day in the DN group and 0.93 ± 0.06 mEq/day in the 2K1C + DN group) (Figure 3). The levels of potassium excretion were similar in all groups (data not shown).

Bottom Line: Arterial blood pressure, water intake, urine volume, and sodium excretion were measured.L-arg and denervation induced increases in water intake and urine volume, and L-arg caused a significant natriuretic effect.Our results suggest that renal sympathetic activity participates in the genesis and the maintenance of the hypertension and also demonstrate that treatment with L-arg alone is incapable of normalizing the MAP and that the effect of such treatment is not additive with the effect of kidney denervation.

View Article: PubMed Central - PubMed

Affiliation: Department of Physiological Sciences, Health Sciences Center, Federal University of Espírito Santo, Avenida Marechal Campos 1456, 29040-577 Vitória, ES, Brazil.

ABSTRACT
The purpose was to determine the role of renal nerves in mediating the effects of antihypertensive treatment with L-arginine in a renovascular hypertension model. The 2K1C (two-kidney one-clip model) hypertensive rats were submitted to bilateral surgical-pharmacological renal denervation. The animals were subdivided into six experimental groups: normotensive control rats (SHAM), 2K1C rats, 2K1C rats treated with L-arginine (2K1C + L-arg), denervated normotensive (DN) rats, denervated 2K1C (2K1C + DN) rats, and denervated 2K1C + L-arg (2K1C + DN + L-arg) rats. Arterial blood pressure, water intake, urine volume, and sodium excretion were measured. The 2K1C rats exhibited an increase in the mean arterial pressure (MAP) (from 106 ± 3 to 183 ± 5.8 mmHg, P < 0.01), whereas L-arg treatment induced a reduction in the MAP (143 ± 3.4 mmHg) without lowering it to the control level. Renal nerve denervation reduced the MAP to normotensive levels in 2K1C rats with or without chronic L-arg treatment. L-arg and denervation induced increases in water intake and urine volume, and L-arg caused a significant natriuretic effect. Our results suggest that renal sympathetic activity participates in the genesis and the maintenance of the hypertension and also demonstrate that treatment with L-arg alone is incapable of normalizing the MAP and that the effect of such treatment is not additive with the effect of kidney denervation.

No MeSH data available.


Related in: MedlinePlus