| Abstract: | The hydroperoxide (HP) of phosphatidylethanolamine, if added to a suspension of vesicles of the sarcoplasmic reticulum (SR), was shown to have a weak activating effect on Ca-dependent ATPase and to increase the permeability of SR membranes for Ca++, measured during activity of the enzyme. HP of linoleic acid did not affect the parameters of the Ca++ transport enzyme system, the activity of Ca++-dependent ATPase, the Ca/ATP ratio, or the rate of outflow of Ca++ in SR membranes on account of the low level of its incorporation into SR fragments. It is concluded that among the primary molecular peroxidation products (HP of free fatty acids, HP of phospholipids), induced both in vitro (by the Fe+++ascorbate system) and in vivo (ischemia, avitaminosis-E), only phospholipid HP is an effective modifier of Ca++ transport in SR membranes.This was a combined research project of the M. V. Lomonosov Moscow State University and the I. M. Sechenov First Moscow Medical Institute.Laboratory of Physical Chemistry of Biomembranes, M. V. Lomonosov Moscow State University. Laboratory for Transplantation of Organs and Tissues, Academy of Medical Sciences of the USSR, and Department of Operative Surgery and Topographic Anatomy, I. M. Sechenov First Moscow Medical Institute. (Presented by Academician of the Academy of Medical Sciences of the USSR V. V. Kovanov.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 87, No. 2, pp. 145–149, February, 1979. |
