Radioprotection of mouse hematopoietic stem cells by leukotriene A4 and lipoxin B4.

Abstract

The potent cyto/radioprotective biological activity induced by leukotrienes prompted a search for other lipoxygenase products exhibiting similar properties. Pretreatment of mice with 1 to 20 μg of leukotriene A4 before sublethal irradiation induced an increase in the number of endogenous hematopoietic stem cells. Radioprotection was also provided by pretreatment with lipoxin B4, but not with lipoxin A4 or with potential lipoxin precursors: 5-HETE, 15-HPETE, 15-HETE, and arachidonic acid. The degree of protection induced by leukotriene A4 or lipoxin B4 is less than that previously reported for an equivalent dose of leukotriene C4. Administration of the lipoxins did not result in any visibly detectable side effects such as diarrhea or ataxia.