昆虫激素对家蚕不同组织 Bẞ-N-乙酰 葡萄糖苷酶活性的影响.

【Objective】We investigated the changes of GlcNAcases activity in different tissues of the fifth instar of Bombyx mori after treatment with 20-hydroxyecdysone (20E) and Juvenile hormone (JH) respectively, aiming to provide references for the further analysis of the biological function of β-N-acetylgucosaminidase (GlcNAcases）.【Method】The changes of GlcNAcases activity in hemolymph, fatbody, midgut, integument and silkgland of silkworm larvae were measured and analyzed by spectrophotometry at 6, 12, 18, 24 and 48 h after injecting 20E and JH with microinjector.【Result】In the JH treatment group, the GlcNAcases activity began to increase significantly at 12 h and continued to be significantly higher than that in the control group at 18, 24 and 48 h in hemolymph. However, after 20E treatment, the GlcNAcases activity was significantly higher than that in the control group only at 24 and 48 h. After 20E or JH treatment, the changes of GlcNAcases activity was similar in fatbody. There was no significant change at 6, 12 and 18 h, but the GlcNAcases activity was significantly higher than that of the control group at 24 and 48 h. In the midgut, the GlcNAcases activity was slightly higher than that of the control group at 6 and 12 h after 20E or JH treatment, but the difference was not significant compared with the control group. However, the GlcNAcases activity was significantly higher than that of the control group at 18 h and continued to increase at 24 h. After that, it began to decrease to the level of the control group at 48 h. In the integument, the GlcNAcases activity was significantly higher than that of the control group at 12 h and continued to be significantly higher at 18 and 24 h, but it decreased to the level of the control group at 48 h after 20E treatment. While in JH treatment group, the GlcNAcases activity was significantly lower than that of the control group at 12, 18 and 24 h and recovered to the level of the control group at 48 h. In the silkgland, the GlcNAcases was higher than that of the control group at 12 h after 20E treatment, but the difference was not significant. Thereafter, the enzyme activity continued to increase and were significantly higher than that of the control group at 18 and 24 h. At 48 h, the enzyme activity decreased to a certain extent, but was still significantly higher than that of the control group. In the JH treatment group, the enzyme activity began to decrease from 12 to 48 h and the difference reached a significant or extremely significant level compared with the control group at 18, 24 and 48 h.【Conclusion】20E and JH could activate GlcNAcases activity in the hemolymph, fatbody and midgut of silkworm larvae. However, in the integument and silk gland, the GlcNAcases were activated by 20E but inhibited by JH. The results indicated that GlcNAcases plays diverse functions in different tissues of Bombyx mori and the effects of different hormones on the GlcNAcases activity were also distinct. [ABSTRACT FROM AUTHOR]