Left ventricular and renal expression of natriuretic peptide receptors in a hypertensive remmant kidney rat model.

• Type: Summary of Presentation in an International Conference
• Date: 2005

Authors

Santos-Araújo C (Author) FMUP; Roncon-Albuquerque R Jr (Author) FMUP; Faria B (Author) Other; Moreira-Rodrigues M (Author) Other; Sampaio-Maia B (Author) Other; Pestana M (Author) FMUP; Leite-Moreira AF (Author) FMUP

Conference proceedings International

Title: European Journal of Heart Failure

Initial page: 139

ESC Annual Congress 2005

Stockholm, Sweden , 03 a 07 de Setembro de 2005

Scientific classification

FOS: Medical and Health sciences > Other medical sciences

Other information

Resumo (PT): Introduction: Chronic renal insufficiency is characterized by modifications in renal and systemic hemodynamics and in sodium excretion per nephron and is accompanied by changes in circulating levels of natriuretic peptides (NP's). Despite this, the implication of the NP's system in the physiopathology of chronic renal failure hypertension remains to be clarified. The aim of this study was to evaluate the cardiac and renal expression of NPR-A (efector receptor) and NPR-C (clearance receptor) in an experimental model of reduced renal mass. Methods: Male Wistar-Han rats (220g) were submitted to right nephrectomy and excision of both poles of the left kidney (nx, n=20). Controls were Sham operated animals (Sham, n=17). The rats were kept in metabolic cages for the quantification of 24h sodium and creatinine excretion. Systolic (SBP) and diastolic (DBP) blood pressure was evaluated weekly using a tail cuff photoelectric pulse detector. Two, 10 or 26 weeks after the surgery tissue samples from LV, RC and RM were collected for mRNA quantification of NPR-A and NPR-C by RT-PCR, using GAPDH as the housekeeping gene. Also, fragments of RC and RM from all groups were stained with histochemical techniques, for quantification of tubulointerstitial fibrosis and atrophy. Results: At 2, 10 and 26, both SBP and DBP were increased in nx rats but not in sham animals. At 2, 10 and 26, the nx rats presented an increased fractional excretion of sodium, a decreased creatinine clearance and an increase in tubulointerstitial fibrosis and atrophy that was related with the time elapsed post surgery. In the LV from nx rats, the NPR-A and NPR-C mRNA levels were increased at 10 but not at 2 or 26. In the RC from nx rats, the NPR-A expression was increased at 10 and 26 but not at 2 whereas the NPR-C expression was increased only at 10. In the RM from nx rats, NPR-A was downregulated at 2 and 10 but not at 26 whereas the NPR-C expression was decreased only at 10. Conclusions: In this remnant kidney rat model, hypertension is accompanied by a modification in the expression of cardiac and renal NP's receptors. The modulation of NPR-A and NPR-C differs in LV, RC and RM and is related with the time elapsed post surgery. These results suggest the existence of a complex regulation of the NP's system during the time course of chronic renal failure.

Language: English

Type (Professor's evaluation): Scientific

Notes: ESC Annual Congress 2005, published in journal, European Journal of Heart Failure 2005; 4(Suppl.1):139.