Antagonism of action between vitamins a and K1 on the plasma membrane of erythrocytes
Callari, D.; Abate, G.; Billitteri, A.
Bollettino della Societa Italiana di Biologia Sperimentale 54(16): 1533-1539
1978
ISSN/ISBN: 0037-8771 PMID: 743461 Document Number: 137408
Human erythrocytes [RBC] were washed and suspended in a buffered solution to which vitamins A, K1, K3 and E, and BHT (butylated hydroxytoluene) were added. Vitamin K1 at a concentration of 60 .mu.M, in vitro, had a slight hemolytic effect; vitamin K3 was even slighter. Liberation of Hb from RBC treated with K1 was comparable in intensity with that due to vitamin E, but the latter liberated a much larger amount of K+ than vitamin K1. Retinol 60 .mu.M exerted a maximal hemolytic effect; hence, in inhibition studies, only 35 .mu.M was used; 64.0 .+-. 2.2% of Hb was liberated, and 79.4 .+-. 3.2% of K1. The latter reduced liberation of K+. Inhibition of K+ liberation strictly corresponded to the increment in the molecular ratio between phylloquinone and retinol. Vitamin K3 did not modify liberation of K+, and only slightly inhibited the liberation of Hb of RBC treated with retinol. In all tests using K3, formation of methomoglobin was observed. In the presence of vitamin K1, RBC bonded a lesser quantity of retinol, while K3 had an opposite effect. Since peroxidation of lipids of RBC treated with retinol was related to hemolysis by this vitamin, studies were made to determine if inhibition of hemolysis by K1 and K3 was linked to decreased lipoperoxidation of RBC. The latter was increased by vitamin A, while K1 and K3 make no difference, but it was reduced by antioxidants like .alpha.-tocopherol and BHT.