[A study of the role of lipoxygenases in radiation-induced apoptosis of thymocytes. Inhibitory analysis].
The radiation-induced apoptosis of thymocytes is suppressed by the common inhibitor of lipoxygenases nordihydroguaiaretic acid but not the inhibitors of cyclooxygenases or cytochrome P-450, which indicates the key role of lipoxygenases in apoptosis. However, the specific inhibitors of 5-lipoxygenase (AA861) and of 12-lipoxygenase (baicalein) do not suppress apoptosis and even enhance it. This effect can be explained by an increase in the yield of the 15-lipoxygenase product upon inhibition of 5- and 12-lipoxygenases. Indeed, the addition of 15-hydroxyecosotetraenic acid, a product of 15-lipoxygenase, into the incubation medium induces apoptosis in thymocytes. The results obtained suggest that 15-lipoxygenase is one of the enzymes involved in radiation-induced apoptosis of thymocytes.
Grichenko
O E
OE
Institute of Theoretical and Experimental Biophysics, Russian Academy of Sciences, Pushchino, 142290 Russia.
Shaposhnikova
V V
VV
Levitman
M Kh
MKh
Kudriavtsev
A A
AA
Korystov
Iu N
IuN
D000818:Animals; D017209:Apoptosis; D016227:Benzoquinones / Q000494:pharmacology; D002478:Cells, Cultured; D003037:Cobalt Radioisotopes; D004247:DNA / Q000032:analysis; D004586:Electrophoresis; D044950:Flavanones; D005419:Flavonoids / Q000494:pharmacology; D008084:Lipoxygenase / Q000502:physiology*; D016859:Lipoxygenase Inhibitors / Q000494:pharmacology*; D008297:Male; D011829:Radiation Dosage; D051381:Rats; D017208:Rats, Wistar; D013601:T-Lymphocytes; D013950:Thymus Gland / Q000166:cytology / Q000528:radiation effects*
D016227:Benzoquinones; D003037:Cobalt Radioisotopes; D044950:Flavanones; D005419:Flavonoids; D016859:Lipoxygenase Inhibitors; C006680:baicalein; C036837:2,3,5-trimethyl-6-(12-hydroxy-5,10-dodecadiynyl)-1,4-benzoquinone; D004247:DNA; D008084:Lipoxygenase