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Studies on Changes in Toughness of the Body Wall from Sea Cucumber

海参体壁韧性变化的研究

基本信息

批准号：
61560227
负责人：
WATABE Shugo
金额：
$ 1.34万
依托单位：
The University of Tokyo
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (C)
财政年份：
1986
资助国家：
日本
起止时间：
1986 至 1987
项目状态：
已结题

项目摘要

Holothurian body wall rapidly changes its mechanical properties. However, the mechanisms involved are not fully understood. The present study deals with the cation-dependent changes in toughness of holothurian body wall in association with acidic glycosaminoglycan(AGAG).1. The toughness of the body wall from a sea cucumber Stichopus japonicus was 0.6 to 1.4kg in the absence of salt and decreased markedly by monovalent cations, until it reached zero at 0.3M NaCl or 0.4M KCl. The toughness tended to decrease by CaCl_2 and MgCl_2, though the extent was much smaller.2. The specific viscosity (<eta>sp) of holothurian AGAG decreased from 0.7 in the absence of salt to 0.47, 0.51, 0.49, and 0.57 in 0.1M NaCl, KCl, CaCl2, and MgCl_2, respectively. Increase of salt concentration resulted in a successive decrease of <eta>sp with monovalent cations, whereas <eta>sp rather increased with divalent cations.3. Chemical analyses showed that sea cucumber AGAG contained 19% glucuronic acid, 33% N-acetyl galactosamine and 30% SO^<4->, suggesting that it was a kind of chondroitin sulfate.4. Electron micrographs of the thin sections stained with lead citrate showed many collagen fibrils. By ruthenium red staining of the desalted body wall, AGAG was found to be distributed between collagen fibers and in their peripheral portions. When the body wall was treated with NaCl, there occurred some coagulation of thin fibrils as observed by ruthenium red staining.5. It was suggested from these observations that AGAG plays an important role in toughness changes of the body wall of sea cucumber.

海参体壁的力学性质迅速改变。然而，所涉及的机制尚未完全了解。本研究探讨了与酸性糖胺聚糖（AGAG）相关的海参体壁韧性的阳离子依赖性变化.在无盐条件下，海参体壁的韧性为0.6 ~ 1.4kg，一价阳离子使其韧性显著降低，在0.3M NaCl或0.4M KCl时，其韧性为零。CaCl_2和MgCl_2对韧性有降低的趋势，但降低幅度较小.海参AGAG的比粘度（<eta>sp）由无盐时的0.7分别下降到0.1M NaCl、KCl、CaCl_2和MgCl_2中的0.47、0.51、0.49和0.57。随着盐浓度的增加，<eta>一价阳离子的sp值逐渐减小，而<eta>二价阳离子的sp值反而增大.化学分析表明，海参AGAG中含有19%的葡萄糖醛酸、33%的N-乙酰半乳糖胺和30%的<4->硫酸软骨素.用柠檬酸铅染色的薄切片的电子显微镜照片显示许多胶原纤维。通过钌红染色脱盐体壁，发现AGAG分布在胶原纤维之间及其周边部分。当体壁用NaCl处理时，钌红染色观察到一些细纤维的凝固。这些结果表明，AGAG在海参体壁韧性变化中起着重要作用。