RESUMEN
AIMS: Pregnancy is a physiological stage with profound cardiovascular changes leading to hypotension. Preeclampsia (PE) reverts these normal changes inducing hypertension. Renin-angiotensin system (RAS) has been related in PE genesis. It has been reported a novel receptor in the system, the Prorenin/Renin receptor (PRR), with several roles in renal and cardiovascular illnesses. It is not known, however, if PRR changes its expression or is activated during normal or PE-complicated pregnancy on tissues intimately related to hypertension. So, the aim of this work was to describe PRR expression during normal and hypertensive pregnancy in rats. METHODS: We used a subrenal aortic coarctation (SRAC) model in rats. Atria, septum and ventricular heart tissue, aorta and renal tissue samples were homogenized and immunoblotted using anti-PRR and anti-PLZF antibodies. We also measured gene expression by RT-PCR. KEY FINDINGS: Hypertension and proteinuria were observed in SRAC-pregnant rats. In pregnant, non-SRAC rats, PRR showed a higher expression of both, gene and protein compared to non-pregnant rats in heart, aorta and kidney tissues. PE induces a very high expression of PRR in cardiac tissues and, on the contrary, decreases PRR expression in both, aorta and kidney. PLZF, a marker of PRR function, was augmented only in aorta and kidney in non-SRAC pregnant rats. In SRAC-pregnant rats, PLZF increment disappeared. SIGNIFICANCE: These findings indicate that PRR expression changes differently during pregnancy and PE in tissues related to cardiovascular functions and suggest a probable participation of the receptor during normal and preeclamptic pregnancy in the rat.
Asunto(s)
Hipertensión Inducida en el Embarazo/fisiopatología , Preeclampsia/fisiopatología , Proteinuria/fisiopatología , Receptores de Superficie Celular/genética , Sistema Renina-Angiotensina , Animales , Aorta/metabolismo , Modelos Animales de Enfermedad , Femenino , Regulación de la Expresión Génica , Hipertensión Inducida en el Embarazo/genética , Riñón/metabolismo , Preeclampsia/genética , Embarazo , Ratas , Ratas Wistar , Receptores de Superficie Celular/metabolismo , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , ATPasas de Translocación de Protón VacuolaresRESUMEN
The recent finding of a specific receptor for prorrenin/renin (PRR) has brought new insights into the physiology of the renin-angiotensin-aldosterone system. No undoubtable role has been described for this receptor so far. Its role seems to be important in chronic illnesses such as hypertension, possibly participating in the cardiovascular remodeling process, and diabetes where participation in inflammation development has been described. It is not possible, however, to explore the PRR function using classical pharmacological approaches due to the lack of specific agonists or antagonists. Two synthetic peptides have been described to accomplish these roles, but no conclusive data have been provided. There are no X-ray crystallography studies available to describe the structure and potential sites for drug development. So, the aim of this work was to model and theoretically describe the PRR. We describe and characterize the whole receptor protein, its spatial conformation and the potential interactions of PRR with the synthetic peptides available, describing the amino acid residues responsible for these interactions. This information provides the basis for directed development of drugs, seeking to agonize or antagonize PRR activity and study its function in health and ill stages.
Asunto(s)
Simulación de Dinámica Molecular , Conformación Proteica , Receptores de Superficie Celular/química , Renina/química , ATPasas de Translocación de Protón Vacuolares/química , Secuencia de Aminoácidos , Sitios de Unión , Dominio Catalítico , Humanos , Modelos Moleculares , Simulación del Acoplamiento Molecular , Datos de Secuencia Molecular , Unión Proteica , Dominios y Motivos de Interacción de Proteínas , Receptores de Superficie Celular/metabolismo , Renina/metabolismo , Alineación de Secuencia , ATPasas de Translocación de Protón Vacuolares/metabolismoRESUMEN
The in vivo effect of continuous angiotensin II (Ang II) infusion on arterial blood pressure, vascular hypertrophy and α1 -adrenoceptors (α1 -ARs) expression was explored. Alzet(®) minipumps filled with Ang II (200 ng kg(-1) min(-1) ) were subcutaneously implanted in male Wistar rats (3 months-old). Groups of rats were also treated with losartan, an AT1 R antagonist, or with BMY 7378, a selective α1D -AR antagonist. Blood pressure was measured by tail-cuff; after 2 or 4 weeks of treatment, vessels were isolated for functional and structural analyses. Angiotensin II increased systolic blood pressure. Phenylephrine-induced contraction in aorta was greater (40% higher) in Ang II-treated rats than in the controls, and similar effect occurred with KCl 80 mm. Responses in tail arteries were not significantly different among the different groups. Angiotensin II decreased α1D -ARs without modifying the other α1 -ARs and induced an increase in media thickness (hypertrophy) in aorta, while no structural change occurred in tail artery. Losartan prevented and reversed hypertension and hypertrophy, while BMY 7378 prevented and reversed the aorta's hypertrophic response, without preventing or reversing hypertension. Findings indicate that Ang II-induced aortic hypertrophic response involves Ang II-AT1 Rs and α1D -ARs. Angiotensin II-induced α1D -AR-mediated vascular remodeling occurs independently of hypertension. Findings identify a α1D -AR-mediated process whereby Ang II influences aortic hypertrophy independently of blood pressure elevation.
Asunto(s)
Angiotensina II/toxicidad , Hipertensión/inducido químicamente , Hipertensión/fisiopatología , Músculo Liso Vascular/fisiología , Receptores Adrenérgicos alfa 1/fisiología , Bloqueadores del Receptor Tipo 2 de Angiotensina II/farmacología , Animales , Aorta Torácica/efectos de los fármacos , Aorta Torácica/fisiología , Relación Dosis-Respuesta a Droga , Hipertrofia/inducido químicamente , Hipertrofia/metabolismo , Masculino , Músculo Liso Vascular/efectos de los fármacos , Técnicas de Cultivo de Órganos , Ratas , Ratas WistarRESUMEN
The relaxant effect of the methyl ester of rosuvastatin was evaluated on aortic rings from male Wistar rats (250-300 g, 6 rats for each experimental group) with and without endothelium precontracted with 1.0 µM phenylephrine. The methyl ester presented a slightly greater potency than rosuvastatin in relaxing aortic rings, with log IC50 values of -6.88 and -6.07 M, respectively. Unlike rosuvastatin, the effect of its methyl ester was endothelium-independent. Pretreatment with 10 µM indomethacin did not inhibit, and pretreatment with 1 mM mevalonate only modestly inhibited the relaxant effect of the methyl ester. Nω-nitro-L-arginine methyl ester (L-NAME, 10 µM), the selective nitric oxide-2 (NO-2) inhibitor 1400 W (10 µM), tetraethylammonium (TEA, 10 mM), and cycloheximide (10 µM) partially inhibited the relaxant effect of the methyl ester on endothelium-denuded aortic rings. However, the combination of TEA plus either L-NAME or cycloheximide completely inhibited the relaxant effect. Inducible NO synthase (NOS-2) was only present in endothelium-denuded aortic rings, as demonstrated by immunoblot with methyl ester-treated rings. In conclusion, whereas rosuvastatin was associated with a relaxant effect dependent on endothelium and hydroxymethylglutaryl coenzyme A reductase in rat aorta, the methyl ester of rosuvastatin exhibited an endothelium-independent and only slightly hydroxymethylglutaryl coenzyme A reductase-dependent relaxant effect. Both NO produced by NOS-2 and K+ channels are involved in the relaxant effect of the methyl ester of rosuvastatin.
Asunto(s)
Animales , Masculino , Ratas , Aorta/efectos de los fármacos , Endotelio Vascular/efectos de los fármacos , Fluorobencenos/farmacología , Hidroximetilglutaril-CoA Reductasas/efectos de los fármacos , NG-Nitroarginina Metil Éster/farmacología , Pirimidinas/farmacología , Sulfonamidas/farmacología , Vasodilatación/efectos de los fármacos , Vasodilatadores/farmacología , Aorta/enzimología , Cicloheximida/farmacología , Fluorobencenos/química , Óxido Nítrico Sintasa de Tipo II/farmacología , Pirimidinas/química , Ratas Wistar , Sulfonamidas/química , Tetraetilamonio/farmacología , Vasodilatación/fisiologíaRESUMEN
The relaxant effect of the methyl ester of rosuvastatin was evaluated on aortic rings from male Wistar rats (250-300 g, 6 rats for each experimental group) with and without endothelium precontracted with 1.0 µM phenylephrine. The methyl ester presented a slightly greater potency than rosuvastatin in relaxing aortic rings, with log IC50 values of -6.88 and -6.07 M, respectively. Unlike rosuvastatin, the effect of its methyl ester was endothelium-independent. Pretreatment with 10 µM indomethacin did not inhibit, and pretreatment with 1 mM mevalonate only modestly inhibited the relaxant effect of the methyl ester. Nω-nitro-L-arginine methyl ester (L-NAME, 10 µM), the selective nitric oxide-2 (NO-2) inhibitor 1400 W (10 µM), tetraethylammonium (TEA, 10 mM), and cycloheximide (10 µM) partially inhibited the relaxant effect of the methyl ester on endothelium-denuded aortic rings. However, the combination of TEA plus either L-NAME or cycloheximide completely inhibited the relaxant effect. Inducible NO synthase (NOS-2) was only present in endothelium-denuded aortic rings, as demonstrated by immunoblot with methyl ester-treated rings. In conclusion, whereas rosuvastatin was associated with a relaxant effect dependent on endothelium and hydroxymethylglutaryl coenzyme A reductase in rat aorta, the methyl ester of rosuvastatin exhibited an endothelium-independent and only slightly hydroxymethylglutaryl coenzyme A reductase-dependent relaxant effect. Both NO produced by NOS-2 and K+ channels are involved in the relaxant effect of the methyl ester of rosuvastatin.