Effect of angiotensin-(1-7) on ATPase activities in several tissues.
The present investigation was undertaken to determine whether Ang-(1-7) is able to modify ATPase activities in membrane fractions prepared from several tissues. In the presence of 10(-6) M Ang-(1-7), total (Na , K+, Mg2+)-ATPase activity decreased 31% in rat atrium and 13% in sheep atrium but was unmodified in sheep liver, rat ventricle or crude brain membranes. In rat brain synaptosomal membranes, Ang-(1-7) at 10(-8) and 10(-7) M concentrations activated Na+, K+-ATPase 20 and 24%, respectively. Rat kidney Na+, K+-ATPase activity decreased roughly 40-70% with 10(-10)-10(-6) M Ang-(1-7)), but increased 22% with 10(-12) M peptide concentration, thus indicating a biphasic effect. Our findings showing that ATPase from several tissues responds differently to Ang-(1-7) are attributable to enzyme tissue specificity.
López Ordieres
M G
MG
Instituto de Biología Celular y Neurociencias Prof. E. De Robertis, Facultad de Medicina, Universidad de Buenos Aires, Argentina.
Gironacci
M
M
Rodríguez de Lores Arnaiz
G
G
Peña
C
C
D000803:Angiotensin I; D000804:Angiotensin II / Q000494:pharmacology*; D000818:Animals; D001921:Brain / Q000187:drug effects / Q000201:enzymology; D017301:Ca(2+) Mg(2+)-ATPase / Q000378:metabolism*; D007668:Kidney / Q000187:drug effects / Q000201:enzymology; D008099:Liver / Q000187:drug effects / Q000201:enzymology; D009206:Myocardium / Q000201:enzymology; D010446:Peptide Fragments / Q000494:pharmacology*; D051381:Rats; D017208:Rats, Wistar; D012756:Sheep; D000254:Sodium-Potassium-Exchanging ATPase / Q000378:metabolism*; D013574:Synaptosomes / Q000187:drug effects / Q000201:enzymology
D010446:Peptide Fragments; D000804:Angiotensin II; D000803:Angiotensin I; D017301:Ca(2+) Mg(2+)-ATPase; D000254:Sodium-Potassium-Exchanging ATPase; C118790:angiotensin I (1-7)