triethyllead and Carcinoma--Ehrlich-Tumor

The influence of triethyl lead (TriEL) on the activity of plasma membrane-bound enzymes of Ehrlich ascites tumor cells and on membrane fluidity has been investigated. TriEL completely inhibits the (Na+-K+)-ATPase in its membrane-bound and even more pronounced in its solubilized form between 5 and about 20 microM. It also alters the microviscosity of the isolated plasma membrane up to a temperature of about 30 degrees C, but it does not have any influence on the fluidity of the membrane-derived liposomes. From these data it is concluded that the inhibitor may interact directly with the catalytic subunit of the (Na+ + K+)-ATPase, and may not exert its influence by interfering with the membrane lipids.

Topics: 5'-Nucleotidase; Adenosine Triphosphatases; Alkaline Phosphatase; Animals; Ca(2+) Mg(2+)-ATPase; Carcinoma, Ehrlich Tumor; Cell Membrane; Fluorescence Polarization; Kinetics; Lead; Membrane Fluidity; Mice; Nucleotidases; Organometallic Compounds; Sodium-Potassium-Exchanging ATPase; Viscosity