Grichenko O E, Shaposhnikova V V, Levitman M Kh, Kudriavtsev A A, Korystov Iu N
Institute of Theoretical and Experimental Biophysics, Russian Academy of Sciences, Pushchino, 142290 Russia.
Radiats Biol Radioecol. 2004 Jan-Feb;44(1):27-31.
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.
脂氧合酶的常见抑制剂去甲二氢愈创木酸可抑制辐射诱导的胸腺细胞凋亡，但环氧化酶或细胞色素P - 450的抑制剂则不能，这表明脂氧合酶在细胞凋亡中起关键作用。然而，5 - 脂氧合酶的特异性抑制剂（AA861）和12 - 脂氧合酶的特异性抑制剂（黄芩苷）并不能抑制细胞凋亡，甚至会增强细胞凋亡。这种效应可以通过抑制5 - 脂氧合酶和12 - 脂氧合酶后15 - 脂氧合酶产物产量的增加来解释。事实上，向孵育培养基中添加15 - 脂氧合酶的产物15 - 羟基二十碳四烯酸可诱导胸腺细胞凋亡。所得结果表明，15 - 脂氧合酶是参与辐射诱导胸腺细胞凋亡的酶之一。
