Tesoriere G, Tesoriere L, Giuliano M, Vento R
FEBS Lett. 1983 Nov 28;164(1):166-70. doi: 10.1016/0014-5793(83)80042-8.
Thymidine kinase in chick embryo retina reaches its highest values on the 8-10th day of development, then declines reaching the lowest value at hatching. The rate of DNA synthesis essentially follows this activity while, in contrast, nucleoside phosphotransferase increases progressively during development. Glucocorticoids at 5 X 10(-6) M lower the level of thymidine kinase in isolated retinas of chick embryo. The most effective steroid was hydrocortisone. The effect was observed in retinas from 8-18-day-old chick embryo and, except on the 8th day, was always of the same magnitude. We suggest that a glucocorticoid can be the natural factor responsible for the marked fall in thymidine kinase during development. Brief periods of exposure to steroids increase nucleoside phosphotransferase activity in isolated chick embryo retinas. When the exposure was longer than 3 h this activity was also clearly decreased. We conclude that other factors are responsible for the natural increment which occurs for this activity during development.
鸡胚视网膜中的胸苷激酶在发育的第8至10天达到最高值，然后下降，在孵化时达到最低值。DNA合成速率基本遵循这一活性，而相比之下，核苷磷酸转移酶在发育过程中逐渐增加。5×10⁻⁶ M的糖皮质激素可降低鸡胚分离视网膜中胸苷激酶的水平。最有效的类固醇是氢化可的松。在8至18日龄鸡胚的视网膜中观察到了这种效应，除了第8天，其效应总是相同程度的。我们认为糖皮质激素可能是发育过程中胸苷激酶显著下降的天然因素。短时间暴露于类固醇可增加鸡胚分离视网膜中的核苷磷酸转移酶活性。当暴露时间超过3小时时，该活性也明显降低。我们得出结论，其他因素导致了发育过程中该活性的自然增加。
