Studies On The Immune Mechanism Of Body Surface And Mucus In Octopus Ocellatus

From March 2004 to February 2007, the immune mechanism of Octopus ocellatus, which distributed extensively in the littoral of China, was primarily studied. The defence barrier function of the mantle, foot, gill and digestive system of Octopus ocellatus were studied with the methods of histology, histochemical localization and biochemical technique. These organs or tissues were often contacted to the seawater closely.Mucous cells in the mantle, foot, gill and digestive system of Octopus ocellatus were observed and analyzed by the method of AB-PAS (Alcian blue and periodic acid Schiff reaction) combined procedure. According to colors of mucous cells, the mucous cells could be divided into four types: typeⅠ, pure red, presented PAS positive reaction, but AB negative reaction, the content of neutral mucoplysaccharides was abundant; typeⅡ, pure blue, PAS negative reaction, AB positive reaction, the content of acid mucoplysaccharides was rich; typeⅢ, purple reddish; typeⅣ, blue purple. The mucous cells of typeⅢand typeⅣpresented both PAS and AB positively.The mucous cells were rich in the outer epithelia of mantle and arms, the inner and outer epithelia of funnel. There were four types of mucous cells in the epithelia of mantle, most of them were typeⅢand typeⅣ, and the density of mucous cells in the mantle epithelia of the ventral truck was higher than in the dorsal truck. In arms, there were many mucous cells in epithelia of folds, and a few in the other parts , most of them were typeⅡ, a few of them were typeⅢand typeⅣ. In sucker, there were many typeⅡmucous cells in the outer epithelia. The mucous cells were rich in the inner and outer epithelia of funnel, most of them were typeⅡin the base of the funnel and most of them were typeⅢin other parts of the funnel. There were no mucous cells in the epithelia of branchial filaments,and few in the epithelia of branchial axis, but in the whole epithelia of branchial axis and branchial filaments there were some materials which were positive reaction in both AB and PAS. The mucous cells were not observed in esophagus, crop and stomach, but there were large amounts of red materials which presented neutral mucoplysaccharides positivity in the cuticula, epithelial lining, submucosa and stratum submucosum. While in hepatopancreas there were no mucous cells yet, but the red materials are rich in the epithelia and the gland duct.There were mucous cells in peristomal membrane, buccal mass, stomachic caecum, intestine, rectum, flank valvae of anus, anterior and posterior salivary gland. The mucous cells in outer epithelium of the peristomal membrane were abundant, and most of them were typeⅡ; The mucous cells in basal portion of stomachic caecum lateral folds were rich, and most of them were typeⅠ; the type of mucous cells in the middle of lateral folds was onlyⅡ; in the free-end of lateral folds, all mucous cells were typeⅠ. Many mucous cells were observed in epithelia of intestine, rectum and flank valvae of anus, most of them were typeⅡ. There were many mucous cells in the anterior and posterior salivary gland, and most mucous cells in anterior salivary gland were typeⅡand typeⅢ, in posterior salivary gland, typeⅣwas the most. The types and distribution of mucous cells are closely related to the function of these organs.Two kinds of hydrolase including acid phosphatase (ACP) and non-specific esterase (NSE), as well as two kinds of oxidase including peroxidase(POD) and phenoloxidase (PO) in the mantle, foots, digestive system and gill of Octopus ocellatus were studied by histochemical localisation technique. The histochemical results of two kinds of hydrolase were very similar to each other. And the outer epithelia of the mantle, arms, branchial axis and branchial filaments, epithelial lining of whole digestive tube, lobules and ducts of liver presented ACP and NSE positive reactions or very strong positive reactions, as well as the inner and outer epithelia of funnel; the connective tissues of most organs presented weakly positive reaction, but there were some materials which were presented positivity or very strong positivity distributed dispersedly; the muscle tissues of all kinds of organs presented positivity too. All kinds of organs presented weak POD positive reaction, but the distribution rule of the positive materials was similar to that of two kinds of hydrolase. But the distribution rule of the PO was very different, the epithelia of all kinds of organs presented nearly negativity, and the positive materials was only observed in the connective tissues. The reactions results of four enzymes in the cuticula of esophagus, crop and stomach were differert to each other too. The cuticula of esophagus and crop presented very strong NSE positivity, strong POD positivity as well. And the cuticula of stomach presented NSE positivity, but POD positivity was very weak. However, there were 7-15μm thick materials strip of POD positivity between the epithelial cells of stomach and cuticula. The cuticula of esophagus, crop and stomach presented ACP negativity, PO as well.The POD, NSE and POD activity levels were assayed in the mucus secreted by the mucous cells of body surface and homogenate supernatant of some parts of organs (the outer epithelia of mantle, gill, esophagus, crop, stomach, stomachic caecum and intestine). The activities of the three enzymes were detected in the mucus and aforesaid organs. The activity levels of ACP were the highest in the gill. The activities of POD and NSE were the highest in the mantle; but the weakest activities of ACP were stomachic caecum, of NSE were esophagus and of POD were gill; but the the three enzymes activities levels of mucus were medium in the eight samples. These results indicated that the mucus of body surface and skins could hydrolyze and kill the invasive microbacterium to perform barrier function of immunity through the hydrolytic function of ACP and NSE, the bactericidal system of POD-H2O2-Halide and the functions of mucoplysaccharides and so on. Some tissues including the epithelia of gill, as well as digestive systems and so on, which were often contacted to the seawater closely, could also play important roles of immune defensive functions; but PO should not play the direct roles of immune defensive functions about body surface.