Spleen lipids: effect of whole body gamma irradiation and radioprotective chemicals.
Effect of whole body gamma irradiation (1200 r) on spleen lipid metabolism of male and female rats 24 hrs and 48 hrs after irradiation and the effect of radioprotective chemicals vis. AET, serotonin, their mixture and cystamine on radiation induced changes in spleen lipid metabolism has been studied. In male rats both 24 and 48 hrs after irradiation a significant increase in spleen total lipids, cholesterol, phospholipids, phosphatidylethanolamine and phosphatidylcholine was observed. Administration of AET before irradiation prevented the changes in spleen total lipids and cholesterol but not in phospholipids, which was prevented by prior administration of both serotonin and the mixture of serotonin and AET. In female rats 24 hrs after irradiation only spleen total lipids showed an increase which was prevented by prior administration of cystamine. In male rats, 24 hrs after irradiation the incorporation of NaH2 32PO4 (counts/min/ug PLP and counts/min/g spleen) into spleen total phospholipids, phosphatidylcholine and phosphatidylethanolamine was reduced and this was corrected by prior administration of AET. Serotonin and the mixture of serotonin + AET did not protect the specific activity of phosphatidy choline. In female rats irradiation increased the incorporation of NaH2 32PO4 into phosphatidylcholine, which was not prevented by prior administration of cystamine. The fatty acid composition of spleen lipid of female rats was profoundly altered 24 hrs after irradiation. Palmitic acid and oleic acid showed an increase whereas arachidonic and fatty acid above arachidonic acid showed an decrease, which were corrected by administration of cystamine before irradiation.