Sex differences in erythrocyte membrane ATPase activities evidenced by exposing the cells to different hemolytic solutions.
Erythrocytes from twenty-five normal subjects were hemolyzed in both 20 mM imidazole and in ice-cold deionized water to determine their effects on membrane enzyme activities and protein concentration. Erythrocyte (Ca++)ATPase activity and membrane protein concentration were significantly different (p less than 0.01) following different hemolyses, whereas (Na+-K)ATPase and (Mg++)ATPase activities were not significantly affected. In order to test the influence of sex, erythrocyte protein concentration and enzyme activities were studied separately in male and female groups after each hemolytic solution. After hemolysis in water, females showed a significant increase in erythrocyte protein concentration (p less than 0.01) and in (Mg++)ATPase activity (p less than 0.005), whereas males showed a significant decrease in (Ca++)ATPase activity (p less than 0.02). The most reproducible results were obtained in the male group and after hemolysis in water. Females showed a significant lower mean value of cellular Na+ content (p less than 0.005) and higher mean value of K+ content as compared to males. A significant inverse relationship was found between cellular Na+ content and (Na+-K+)ATPase activity in all subjects studied (p less than 0.05). The results confirm that sex-related differences are present in the erythrocyte membrane so that hemolytic solutions in males and females can expose to a different extent membrane-bound proteins and latent ATPases.
Finotti
P
P
Department of Pharmacology, University of Padova, Italy.
Verbaro
R
R
D000251:Adenosine Triphosphatases / Q000097:blood*; D000293:Adolescent; D000328:Adult; D001798:Blood Proteins / Q000378:metabolism; D004910:Erythrocyte Membrane / Q000201:enzymology*; D005260:Female; D006461:Hemolysis / Q000187:drug effects*; D006801:Humans; D007093:Imidazoles / Q000494:pharmacology; D008297:Male; D008875:Middle Aged; D011188:Potassium / Q000097:blood; D012737:Sex Factors; D012964:Sodium / Q000097:blood
D001798:Blood Proteins; D007093:Imidazoles; D012964:Sodium; D000251:Adenosine Triphosphatases; D011188:Potassium