The effect of saponins from Ampelozizyphus amazonicus Ducke on the renal Na+ pumps’ activities and urinary excretion of natriuretic peptides

BMC Complementary and Alternative Medicine

Research Article

Lúcio Ricardo Leite Diniz¹  Viviane Gomes Portella¹  Flávia Magalhães Cardoso¹  Maria Aparecida Ribeiro Vieira¹  Adelina Martha dos Reis¹  Geovanni Dantas Cassali²  Aloa Machado de Souza³  Celso Caruso-Neves³  MariadasGraçasLins Brandão⁴ 

[1] Departamento de Fisiologia e Biofísica, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Av. Antônio Carlos, 6627, 31270-901, Belo Horizonte, Minas Gerais, Brazil;Departamento de Patologia Geral, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Av. Antônio Carlos, 6627, 31270-901, Belo Horizonte, Minas Gerais, Brazil;Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, CCS-Bloco G, Rio de Janeiro, 21949-900, Brazil;Laboratório de Pharmacognosia, Faculdade de Farmácia, Universidade Federal de Minas Gerais, Av. Antônio Carlos, 6627, 31270-901, Belo Horizonte, Minas Gerais, Brazil;

关键词: Ampelozizyphus amazonicus;    Rhamnaceae;    saponins;    antidiuresis;    Na-ATPase;    (Na,K)-ATPase;    atrial natriuretic peptides;   

DOI  :  10.1186/1472-6882-12-40

 received in 2011-09-22, accepted in 2012-04-11,  发布年份 2012

来源: Springer

【 摘 要 】

BackgroundIn a previous study, we showed that a saponin mixture isolated from the roots of Ampelozizyphus amazonicus Ducke (SAPAa D) reduces urine excretion in rats that were given an oral loading of 0.9 % NaCl (4 ml/100 g body weight). In the present study, we investigated whether atrial natriuretic peptides (ANP) and renal ATPases play a role in the SAPAa D- induced antidiuresis in rats.MethodsTo evaluate the effect of SAPAa D on furosemide-induced diuresis, Wistar rats (250-300 g) were given an oral loading of physiological solution (0.9 % NaCl, 4 ml/100 g body weight) to impose a uniform water and salt state. The solution containing furosemide (Furo, 13 mg/kg) was given 30 min after rats were orally treated with 50 mg/kg SAPAa D (SAPAaD + Furo) or 0.5 ml of 0.9 % NaCl (NaCl + Furo). In the SAPAaD + NaCl group, rats were pretreated with SAPAa D and 30 min later they received the oral loading of physiological solution. Animals were individually housed in metabolic cages, and urine volume was measured every 30 min throughout the experiment (3 h). To investigate the role of ANP and renal Na+ pumps on antidiuretic effects promoted by SAPAa D, rats were given the physiological solution (as above) containing SAPAa D (50 mg/kg). After 90 min, samples of urine and blood from the last 30 min were collected. Kidneys and atria were also removed after previous anesthesia. ANP was measured by radioimmunoassay (RIA) and renal cortical activities of Na+- and (Na+,K+)-ATPases were calculated from the difference between the [32P] Pi released in the absence and presence of 1 mM furosemide/2 mM ouabain and in the absence and presence of 1 mM ouabain, respectively.ResultsIt was observed that SAPAa D inhibited furosemide-induced diuresis (at 90 min: from 10.0 ± 1.0 mL, NaCl + Furo group, n = 5, to 5.9 ± 1.0 mL, SAPAaD + Furo group n = 5, p < 0.05), increased both Na+-ATPase (from 25.0 ± 5.9 nmol Pi.mg-1.min-1, control, to 52.7 ± 8.9 nmol Pi.mg-1.min-1, p < 0.05) and (Na+,K+)-ATPase (from 47.8 ± 13.3 nmol Pi.mg-1.min-1, control, to 79.8 ± 6.9 nmol Pi .mg-1.min-1, p < 0.05) activities in the renal cortex. SAPAa D also lowered urine ANP (from 792 ± 132 pg/mL, control, to 299 ± 88 pg/mL, p < 0.01) and had no effect on plasma or atrial ANP.ConclusionWe concluded that the SAPAa D antidiuretic effect may be due to an increase in the renal activities of Na+- and (Na+,K+)-ATPases and/or a decrease in the renal ANP.

【 授权许可】

Unknown   
© Diniz et al.; licensee BioMed Central Ltd. 2012. This article is published under license to BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.