[Release of arachidonate from rat spleen lymphocytes after irradiation].

After spleen lymphocytes incubation with 14C-arachidonic acid 14C label was found associated predominantly with phosphatidylethanolamine (PE) and phosphatidylcholine (PC). Addition of 0.5 mkM a 23187 to the incubation media with 2 mM CaCl2 caused a 4-fold increase in release of labeled free arachidonate in lymphocytes of the control animals.

[Phospholipase A2 in the biochemical mechanisms of spleen lymphocyte reaction to x-ray irradiation of animals].

Preincubation of rat splenic lymphocytes with nonspecific mitogens and calcium ionophore A23187 led to the activity of phospholipase A2 which hydrolyzed arachidonoyl phospholipids and to increased cellular levels of free arachidonic acid. The effect of some substances was decreased as follows: A23187 > > lipopolysaccharide > phytohemagglutinin > concanavalin A. Dose-dependent activation of phospholipid hydrolysis and arachidonic acid release were observed within 6-12 hrs after X-ray irradiation of animals in doses of 0.

[Phospholipase A2 from rat spleen lymphocytes hydrolyzing arachidonoyl-phospholipids].

Phospholipase A2 activity in the postnuclear supernatant of lymphocytes has been studied by measuring 14C arachidonate released from labelled phosphatidyl ethanolamine (PE) and phosphatidyl choline (PC) as exogenous substrates. The pH optimum was 7.5-9.

[The content of cyclic nucleotides, free cytoplasmic Ca2+ and malondialdehyde in the splenic lymphocytes and thymocytes of rats under the action of moderate doses of radiation].

It has been shown that the malonic dialdehyde (MDA) content in spleen lymphocytes of rats increases after whole-body X irradiation with a dose of 0.5 Gy to reach the maximum level in 24 h. Simultaneously, the concentration of cGMP and free cytosol Ca2+ increases.

[Lipid peroxidation of rat spleen and thymus lymphocytes treated with x-rays (0-5-1.0 Gy)].

It is established, that low doses of X-ray irradiation have affected activation of lipid peroxidation (LPO) in immunocompetent cells of the spleen and thymus. The amount of malonic dialdehyde (MDA) in lymphocytes of spleen and thymocytes increases 2 times twenty-four hours after animals' irradiation by X-rays in a dose of 0.5 Gy; when a dose grows to 1.