. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. 312 V. J. SMITH AND K. SODERHALL 60 r. Incubation time (hours) FIGURE 13. Hemocyte count (THC) of ('. mucnas injected with sterile CS (- A -). Injection and bleeding procedures as in Materials and Methods, and at each time interval, the values given are means of groups of 8 animals ± standard deviation. The time zero count (- O -) was obtained from 10 untreated crabs. to have been initiated. In mammals, jtM,3 glucans are known to promote a hyper- phagocytic state in vivo (Di Luzio, 1979) and to activate macrophages directly
. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. 312 V. J. SMITH AND K. SODERHALL 60 r. Incubation time (hours) FIGURE 13. Hemocyte count (THC) of ('. mucnas injected with sterile CS (- A -). Injection and bleeding procedures as in Materials and Methods, and at each time interval, the values given are means of groups of 8 animals ± standard deviation. The time zero count (- O -) was obtained from 10 untreated crabs. to have been initiated. In mammals, jtM,3 glucans are known to promote a hyper- phagocytic state in vivo (Di Luzio, 1979) and to activate macrophages directly in vitro (Seljelid el cil., 1981), but this is the first report of their effect on cell behavior in invertebrates. Regarding the mechanism(s) through which the glucans exert their influence in crustaceans, it is unlikely that they act through specific agglutinin mediated receptors on the hemocyte surface as proposed for opsonic phenomena reported in other vertebrates (McKay and Jenkin, 1970; Renwrantz and Cheng, 1977), since agglu- tinating activity against Moraxella sp. is absent from C. maenas serum (Smith and Ratcliffe, 1978), and, in the present study, changes in the titre of erythrocyte ag- glutinins were not detected following glucan incubation. Instead, in A. astacus, f3- 1,3 glucans are known to specifically activate prophenoloxidase, in the hemocytes, through a complex enzyme cascade involving at least one serine protease (Soderhall. 1982, 1983) and a similar system, also activated by jtM,3 glucans, appears to exist in C. maenas. After activation, phenoloxidase is sticky and will attach to many different types of foreign surface including glass, plastic or fungal spores (Soderhall el ai, 1979), so that it could have facilitated the binding and subsequent ingestion of the bacteria by the cells in the present study. Certainly, in A. astacus the glucans were seen to promote degranulation of the cells in the monolayers, and although it was impossible to observe equivalent
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Keywords: ., bookauthorlilliefrankrat, booksubjectbiology, booksubjectzoology
