Regulation of crustacean molting: a review and our perspectives

Molting is a highly complex process that requires precise coordination to be successful. We describe the early classical endocrinological experiments that elucidated the hormones and glands responsible for this process. We then describe the more recent experiments that have provided information on the cellular and molecular aspects of molting. In addition to providing a review of the scientific literature, we have also included our perspectives.     

14种中药提取成分对酪氨酸酶活性的抑制作用

目的 寻找更合理的试管内分析方法研究药物对体外酪氨酸酶活性的调节,筛选对酪氨酸酶活性抑制作用显著的中药有效成分。方法 采用蘑菇酪氨酸酶多巴速率氧化法测定酪氨酸酶活性,观察14种中药有效成分在试管内对酪氨酸酶系统的调节作用。结果 10种中药提取的成分在不同浓度对酪氨酸酶活性、黑素生成量上显示了剂量依赖性抑制。其中丁香酚、姜黄油、没食子酸、丁香酚和姜黄素复合物(1:1)以及前两者与蜕皮激素(ecdysone)的复合物(1:1:1)对酪氨酸酶抑制活性与单体化合物熊果甙比较差异有显著性(P<0.05);丁香酚、姜黄油对酪氨酸酶呈竞争性抑制,没食子酸呈反竞争性抑制。结论 丁香酚、姜黄素、没食子酸和其他中药有效成分对酪氨酸酶具有体外抑制作用。