α2A-Adrenoceptors Modulate Renal Sympathetic Neurotransmission and Protect against Hypertensive Kidney Disease.
J Am Soc Nephrol
; 31(4): 783-798, 2020 04.
Article
en En
| MEDLINE
| ID: mdl-32086277
ABSTRACT
BACKGROUND:
Increased nerve activity causes hypertension and kidney disease. Recent studies suggest that renal denervation reduces BP in patients with hypertension. Renal NE release is regulated by prejunctional α2A-adrenoceptors on sympathetic nerves, and α2A-adrenoceptors act as autoreceptors by binding endogenous NE to inhibit its own release. However, the role of α2A-adrenoceptors in the pathogenesis of hypertensive kidney disease is unknown.METHODS:
We investigated effects of α2A-adrenoceptor-regulated renal NE release on the development of angiotensin II-dependent hypertension and kidney disease. In uninephrectomized wild-type and α2A-adrenoceptor-knockout mice, we induced hypertensive kidney disease by infusing AngII for 28 days.RESULTS:
Urinary NE excretion and BP did not differ between normotensive α2A-adrenoceptor-knockout mice and wild-type mice at baseline. However, NE excretion increased during AngII treatment, with the knockout mice displaying NE levels that were significantly higher than those of wild-type mice. Accordingly, the α2A-adrenoceptor-knockout mice exhibited a systolic BP increase, which was about 40 mm Hg higher than that found in wild-type mice, and more extensive kidney damage. In isolated kidneys, AngII-enhanced renal nerve stimulation induced NE release and pressor responses to a greater extent in kidneys from α2A-adrenoceptor-knockout mice. Activation of specific sodium transporters accompanied the exaggerated hypertensive BP response in α2A-adrenoceptor-deficient kidneys. These effects depend on renal nerves, as demonstrated by reduced severity of AngII-mediated hypertension and improved kidney function observed in α2A-adrenoceptor-knockout mice after renal denervation.CONCLUSIONS:
Our findings reveal a protective role of prejunctional inhibitory α2A-adrenoceptors in pathophysiologic conditions with an activated renin-angiotensin system, such as hypertensive kidney disease, and support the concept of sympatholytic therapy as a treatment.Palabras clave
Texto completo:
1
Banco de datos:
MEDLINE
Asunto principal:
Sistema Nervioso Simpático
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Receptores Adrenérgicos alfa 2
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Transmisión Sináptica
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Hipertensión Renal
/
Nefritis
Tipo de estudio:
Prognostic_studies
Límite:
Animals
Idioma:
En
Año:
2020
Tipo del documento:
Article