Ueno M, Bidmon H J, Stumpf W E
School of Hygienic Sciences, Kitasato University, Kanagawa, Japan.
Histochemistry. 1992 Aug;98(1):1-6. doi: 10.1007/BF00716931.
The distribution of ecdysteroid binding sites in the stomach and gastrolith disc tissue of crayfish (Procambarus clarkii) was examined in relation to the molting stage by thaw-mount autoradiography. The radiolabeled hormone analogue ponasterone A (25-deoxy-20-hydroxyecdysone) was used. Ecdysteroid binding sites were demonstrated only in certain molting stages, the small gastrolith period and the aftermolt stage. In gastrolith epithelium, ponasterone A binding sites first appeared in the cytoplasm, and then in the nuclei and cytoplasm. In the stomach epithelium, many nuclear binding sites were detectable during the period of gastrolith secretion. These periodical changes in specific ponasterone A binding when correlated with the molting stages clearly show that ecdysteroids may function as an initiator for gastrolith formation and reabsorption. The findings also suggest that ecdysteroids control calcium transport in the stomach epithelium. The time-related and functional differences of cytoplasmic and nuclear concentration of ecdysteroid receptors indicate the presence of cytoplasmic and nuclear receptors associated with specific actions.
通过冷冻切片放射自显影技术，研究了克氏原螯虾（Procambarus clarkii）胃和胃石盘组织中蜕皮甾体结合位点的分布与蜕皮阶段的关系。使用了放射性标记的激素类似物ponasterone A（25-脱氧-20-羟基蜕皮酮）。仅在某些蜕皮阶段，即小胃石期和蜕皮后期，才显示出蜕皮甾体结合位点。在胃石上皮中，ponasterone A结合位点首先出现在细胞质中，然后出现在细胞核和细胞质中。在胃上皮中，在胃石分泌期间可检测到许多核结合位点。特定ponasterone A结合的这些周期性变化与蜕皮阶段相关联，清楚地表明蜕皮甾体可能作为胃石形成和重吸收的启动剂发挥作用。研究结果还表明，蜕皮甾体控制胃上皮中的钙转运。蜕皮甾体受体在细胞质和细胞核中的浓度随时间的变化以及功能差异表明存在与特定作用相关的细胞质和细胞核受体。
