%0 Journal Article
%T The effect of saponins from Ampelozizyphus amazonicus Ducke on the renal Na+ pumps¡¯ activities and urinary excretion of natriuretic peptides
%A Lucio RL Diniz
%A Viviane G Portella
%A Flavia M Cardoso
%A Aloa M Sousa
%A Celso Caruso-Neves
%A Geovanni D Cassali
%A Adelina M Reis
%A Maria GL Brandao
%A Maria AR Vieira
%J BMC Complementary and Alternative Medicine
%D 2012
%I BioMed Central
%R 10.1186/1472-6882-12-40
%X To evaluate the effect of SAPAaD 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 SAPAaD (SAPAaD£¿+£¿Furo) or 0.5£¿ml of 0.9£¿% NaCl (NaCl£¿+£¿Furo). In the SAPAaD£¿+£¿NaCl group, rats were pretreated with SAPAaD 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 SAPAaD, rats were given the physiological solution (as above) containing SAPAaD (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.It was observed that SAPAaD inhibited furosemide-induced diuresis (at 90£¿min: from 10.0£¿¡À£¿1.0£¿mL, NaCl£¿+£¿Furo group, n£¿=£¿5, to 5.9£¿¡À£¿1.0£¿mL, SAPAaD£¿+£¿Furo group n£¿=£¿5, p£¿<£¿0.05), increased both Na+-ATPase (from 25.0£¿¡À£¿5.9£¿nmol Pi.mg-1.min-1, control, to 52.7£¿¡À£¿8.9£¿nmol Pi.mg-1.min-1, p£¿<£¿0.05) and (Na+,K+)-ATPase (from 47.8£¿¡À£¿13.3£¿nmol Pi.mg-1.min-1, control, to 79.8£¿¡À£¿6.9£¿nmol Pi .mg-1.min-1, p£¿<£¿0.05) activities in the renal cortex. SAPAaD also lowered urine ANP (from 792£¿¡À£¿132£¿pg/mL, control, to 299£¿¡À£¿88£¿pg/mL, p£¿<£¿0.01) and had no effect on plasma or atrial ANP.We concluded that the SAPAaD antidiuretic effect may be due to an increase in the renal activities of Na+- and (Na+,K+)-ATPases and/or a decrease in the ren
%K Ampelozizyphus amazonicus Ducke
%K Rhamnaceae
%K saponins
%K antidiuresis
%K Na+-ATPase
%K (Na+
%K K+)-ATPase
%K atrial natriuretic peptides
%U http://www.biomedcentral.com/1472-6882/12/40/abstract