. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. DIGESTION IN LINEUS RUBER Alkaline plwspliatase The gland cells of the gastrodermis normally show no alkaline phosphatase activity but immediately after the Linens has fed, when they are discharging their enzymatic spheres into the gut lumen, intense alkaline phosphatase activity appears around the cell walls (Fig. 7). This localised activity disappears during recon- stitution of the gland cells and so appears to he associated with their secretory rather than recovery phase. The columnar cells of the gastrodermis show at all
. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. DIGESTION IN LINEUS RUBER Alkaline plwspliatase The gland cells of the gastrodermis normally show no alkaline phosphatase activity but immediately after the Linens has fed, when they are discharging their enzymatic spheres into the gut lumen, intense alkaline phosphatase activity appears around the cell walls (Fig. 7). This localised activity disappears during recon- stitution of the gland cells and so appears to he associated with their secretory rather than recovery phase. The columnar cells of the gastrodermis show at all times intense alkaline phos- phatase activity along their free ciliated borders (Fig. 8). The zone of activity varies in depth from a narrow band 3-5 /JL deep immediately below the cilia, to a broad belt which mav extend down into the cells for as much as one-third of 8. FIGURE 8. Longitudinal section of a portion of the foregut (left) and intestine (right) of a starved Linens. Gomori method for alkaline phosphatase. The cells of the foregut show no activity, in marked contrast to those of the intestinal gastrodermis which show intense activity distally. Scale : 1 cm = 50 //. FIGURE 9. Transverse section of an intestinal pouch of Linens four hours after feeding. All the food vacuoles and some of the cytoplasm surrounding them show intense alkaline phosphatase activity. Gomori method. Scale: 1 cm. = 50 their depth. This activity is obviously concerned with some aspect of the digestive function of the gastrodermal cells, for it is completely absent from the cells of the foregut wall (Fig. 8). The distal band of alkaline phosphatase activity persists during extracellular digestion but as phagocytosis and intracellular digestion advance, it spreads down- wards until the entire cytoplasm of the columnar cells gives a positive reaction. The activity is more concentrated around and within the food vacuoles (Fig. 9) and reaches its peak at about the same time as aminopeptidase an
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Keywords: ., bookauthorlilliefrankrat, booksubjectbiology, booksubjectzoology
