1 – Dynamics of the Integument

The main proteins of the haemolymph of Crustacea Decapoda have been identified and analysed: haemocyanin, plasma coagulogen, heteroagglutinins, vitellogenins, and molt-related proteins. All these complex components exhibit a high molecular weight and as oligomeric fractions are able to aggregate or dissociate in subunits according to the composition of medium and experimental procedures. Besides their important role in the defense mechanism, some proteins are involved in the edification of diverse tissues. They are detected within different compartments: soft integument, calcified carapace and hepatopancreas. They are either in transit or sequestered or synthetized within these tissues. In the crayfish Astacus leptodactylus, some components have been identified in different compartments: --in aqueous extracts from soft integument: the haemocyanin, coagulogen and both fraction F1 (lipoprotein with an approximate molecular weight of 45 kdal) and fraction F2 related to the molt. Both coagulogen and fraction F2 appear sometimes as melanized. These two latter fractions exhibit some glucose-mannose residues and they occur with a higher relative amount than in the blood. --in soluble extracts from calcified cuticle: among the numerous fractions showing a high molecular weight, the haemocyanin and coagulogen are detected. --in aqueous extracts from hepatopancreas: both haemocyanin and coagulogen appear with a little relative amount. Components termed as Fa and Fb are found with a high concentration. One minor fraction is also detected. --in aqueous extracts from eggs: the haemocyanin and fraction Fb are present. Other proteins showing only some antigenic identities with those of the haemolymph are also detected in all these tissues. The haemolymph proteins are not present within these compartments following a passive diffusion. Indeed, their relative amount varies according to the tissue investigated and is different from that found in the blood. Except the haemocyanin detected in all tissues with different aggregation states, the haemolymph proteins identified vary in the organs studied. A qualitative and quantitative selection occurs when the blood proteins enter the other compartments. Perhaps some other proteins are not detected following alterations underwent either in the epithelial barriers or during the tannage process or the chitino-proteic complex formation or due to experimental procedures. On the other hand, each tissue has its own proteins. The integument contains crustacyanins alpha, beta, gamma; the eggs are mainly constituted of lipovitellins and the hepatopancreas is rich in small molecular weight proteins and digestive enzymes.(ABSTRACT TRUNCATED AT 400 WORDS)

Etude immunochimique des protéines de divers tissus chez les crustacés décapodes: nature, rôle, origine

Calcium chloride as a biomimetic intermediate for the mineralization of carbonate ions of water as calcium carbonate in gelatinous matrices of chitosan and chitin

Two hydrogels of calcium alginate and chitosan-ca1cium alginate composite were prepared from Na alginate and its composite with chitosan by soaking in 0.1M aq. CaCl 2 . A biomimic fixation of aqueous CO 3 2- ions as CaCO 3 was performed. Each of the hydrogels was put into a dialysis membrane tube, and was soaked in 0.1 M aq. Na 2 CO 3 (pH 11) at room temperature for 1 day to afford a white precipitate of CaCO 3 or chitosan-CaCO 3 and a water-soluble sodium alginate. The dry chitosan-CaCO 3 composite (60% chitosan and 23% CO 3 2 ) was stable in aqueous alkaline solutions and unstable in aqueous acidic solutions.

Chitosan-calcium carbonate composites: Biomimetic mineralization of aqueous carbonate ions into chitosan-ca1cium alginate hydrogels

The incorporation of radioactivity into chitin of the exoskeleton after injection of glucose-1-C14 into the blood of a shore crab, Gaetice depressus, was studied in relation to chitin synthesis at stages of the molting cycle.The ratio of chitin to organic matter was determined to be 67.9% in the completed exoskeleton, but different in each cuticle layer; that is, 22.4% in the exocuticle, 74.9% in the endocuticle, and 63.3% in the membranous layer.During the period of endocuticle formation, the radioactivity was rapidly incorporated into chitin within several hours after the injection of glucose-1-C14, while that in blood decreased correspondingly.Throughout the molting cycle, the highest value of incorporation within 24 hours was shown at one day after molting suggesting that the most active synthesis of chitin occurs at the beginning of endocuticle formation and slows down thereafter with the lapse of time.

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矢野勲

Papers

カニ血中に投与されたGlucose-1-C14の甲殻キチンへの移行について,特に脱皮後の内クチクラ層形成時との関係

矢野 勲

Papers

カニ血中に投与されたGlucose-1-C14の甲殻キチンへの移行について,特に脱皮後の内クチクラ層形成時との関係

矢野勲