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

Autor: Celso Caruso-Neves, Maria Aparecida Ribeiro Vieira, Viviane Gomes Portella, Aloa Machado de Souza, Maria G.L. Brandão, Lúcio Ricardo Leite Diniz, Geovanni Dantas Cassali, Adelina M. Reis, Flávia M. Possato Cardoso
Jazyk: angličtina
Rok vydání: 2012
Předmět:
Zdroj: BMC Complementary and Alternative Medicine, Vol 12, Iss 1, p 40 (2012)
BMC Complementary and Alternative Medicine
ISSN: 1472-6882
Popis: Background In 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. Methods To 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. Results It 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 +-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 +,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 Aa D also lowered urine ANP (from 792 ± 132 pg/mL, control, to 299 ± 88 pg/mL, p Conclusion We 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.
Databáze: OpenAIRE
Externí odkaz: