Influence of whole-body gamma irradiation upon arachidonic acid metabolism in rat platelets

• Published in: Biochimie Vol. 67; no. 9; pp. 1015 - 1021
• Main Authors: Lognonne, J.L., Ducousso, R., Rocquet, G., Kergonou, J.F.
• Format: Journal Article
• Language: English
• Published: Paris Elsevier Masson SAS 01.09.1985; Elsevier
• Subjects: acide arachidonique; Animals; Arachidonic Acid; Arachidonic Acids - blood; Arachidonic Acids - radiation effects; Biological and medical sciences; Biological effects of radiation; Blood Platelets - metabolism; Blood Platelets - radiation effects; Cell Membrane - radiation effects; Fundamental and applied biological sciences. Psychology; Gamma Rays; Ionizing radiations; irradiation; Male; Membrane Lipids - blood; phospholipides; phospholipids; Phospholipids - blood; plaquette; platelet; Platelet Count - radiation effects; Rats; Rats, Inbred Strains; thromboxane; Tissues, organs and organisms biophysics; Whole-Body Irradiation; thromboxane; arachidonic acid; phospholipides; acide arachidonique; plaquette; platelet; phospholipids; irradiation; Vertebrata; Blood cell; Platelet; Mammalia; Gamma radiation; Rat; Rodentia; Phospholipid; Whole body; Arachidonic acid; Metabolism
• ISSN: 0300-9084; 1638-6183
• DOI: 10.1016/S0300-9084(85)80296-0

Les effets de l'irradiation gamma du corps entier (8,4 Gy) sur le métabolisme de l'acide arachidonique (AA) dans les plaquettes de rat ont été étudiés du jour J + 1 au jour J + 10 après irradiation. La conversion d'AA en thromboxane B 2 (TxB 2) est augmentée à J + 1, puis diminue progressivement pour atteindre des valeurs très basses entre J + 7 et J + 10. Cette diminution de la conversion de l'AA exogène en TxB 2 est dûe à un ralentissement de l'incorporation d'AA dans les plaquettes, et non à une diminution des activités cyclooxygénase et thromboxane-synthétase. L'incorporation d'AA dans les phospholipides membranaires des plaquettes est beaucoup plus fortement diminuée que l'incorporation d'AA dans les plaquettes entières; d'autre part, la composition lipidique des membranes plaquettaires est notablement modifiée après irradiation, ce qui doit entraîner des modifications structurales et fonctionnelles dans ces membranes; d'après ces effets de l'irradiation gamma du corps entier sur les plaquettes, les membranes plaquettaires apparaissent comme un site majeur du dommage radiobiologique in vivo dans ces cellules. The effects of whole-body gamma irradiation (8.4 Gy) were studied on arachidonic acid (AA) metabolism in rats' blood platelets, from day D + 1 to day D + 10 after irradiation. AA conversion into thromboxane B 2 (TxB 2) increased at D + 1 and then gradually decreased to very low values from D + 7 to D + 10. This decrease in the conversion of exogenous AA into TxB 2 was due to a lower AA incorporation into platelets and not to a decrease of cyclooxygenase and thromboxane-synthetase activities. AA incorporation into membrane phospholipids of blood platelets was much more decreased than AA incorporation into whole platelets; moreover, the lipid composition of the platelet membranes was markedly modified after irradiation, which must have resulted in structural and functional changes in these membranes; from these effects of whole-body gamma irradiation on platelets, the latter's membranes appeared as a major site of in vivo radiation damage in these cells.