Effect of Aldosterone on the Human Erythrocyte Sodium-Potassium Pump in vitro

1983 ◽  
Vol 64 (2) ◽  
pp. 183-186 ◽  
Author(s):  
N. Stern ◽  
F. Beck ◽  
J. Sowers

1. The effects of aldosterone in vitro on the Na+,K+-dependent ATPase activity of isolated human erythrocyte membranes and on rubidium (86Rb) uptake and [3H]ouabain binding of intact erythrocytes were studied. 2. ATPase activity was nearly doubled (0.061 ± 0.006 to 0.110 ± 0.01 μmol of Pl h−1 mg−1 of protein) by the addition of a physiological concentration of aldosterone (2.7 × 10-10 mol/l). Higher concentrations had no greater effect. 3. Aldosterone had no significant effect on 86Rb uptake or [3H]ouabain binding. 4. Erythrocytes contain aldosterone at concentrations similar to that in plasma. The effect of aldosterone on ATPase is probably maximal.

1993 ◽  
Vol 84 (2) ◽  
pp. 217-223 ◽  
Author(s):  
William D. Lawrence ◽  
Mark R. Deziel ◽  
Paul J. Davis ◽  
Marion Schoenl ◽  
Faith B. Davis ◽  
...  

1. Thyroid hormone (L-thyroxine, 10−10mol/l) incubated in vitro with human erythrocyte membranes induced the release of a soluble calmodulin-like material, the 3′:5′-cyclic nucleotide phosphodiesterase-stimulating activity of which was at least six-fold greater than its concentration measured by a specific calmodulin radioimmunoassay. 2. The material had the characteristics of calmodulin in that it stimulated both phosphodiesterase and erythrocyte Ca2+-ATPase activities, cross-reacted with and was neutralized by anti-calmodulin antibody, was adsorbed by phenothiazine-Sepharose and was heat-stable. Control supernatant from the incubation of membranes in the absence of thyroxine contained calmodulin, the bioactivity of which was not enhanced beyond that predicted from radioimmunoassay. Subsequent addition of thyroxine did not increase calmodulin bioactivity. Calmodulin-agarose removed calmodulin-enhancing activity from the supernatant. 3. Thus, the enhancing factor(s) appears to interact directly with calmodulin. These observations indicate that thyroid hormone promotes the release from human erythrocyte membranes of a soluble factor (or factors) which binds to calmodulin and significantly increases its bioactivity. This enhancing activity is similar to that of a calmodulin activator described in a rat model of hypertension (S.-L. Huang et al., J Clin Invest 1988; 82: 276-81).


1982 ◽  
Vol 121 (2) ◽  
pp. 463-467 ◽  
Author(s):  
Anne Marianne GOLOVTCHENKO-MATSUMOTO ◽  
Isamu MATSUMOTO ◽  
Toshiaki OSAWA

1976 ◽  
Vol 158 (2) ◽  
pp. 497-500 ◽  
Author(s):  
A Brovelli ◽  
G Pallavicini ◽  
F Sinigaglia ◽  
C L Balduini ◽  
C Balduini

Membranes from human O Rhesus-positive erythrocyte ‘ghosts’ were tested in vitro for their ability to digest their own glycoproteins. ‘Ghost’ membranes incubated in Tris/HCl buffer, pH 7.4, release a sialoglycopeptide, which contains glucosamine, galactosamine, galactose and mainly polar amino acids. Chemical composition, molecular size and aggregation properties suggest that this glycopeptide may be a fragment of glycophorin.


2011 ◽  
Vol 406 (3) ◽  
pp. 320-325 ◽  
Author(s):  
Mario Suwalsky ◽  
Pablo Zambrano ◽  
Sigrid Mennickent ◽  
Fernando Villena ◽  
Carlos P. Sotomayor ◽  
...  

Sign in / Sign up

Export Citation Format

Share Document