Studies on the reticuloendothelial system of the dogfish Scyliorhinus canicula. Endocytic activity of fixed cells in the spleen and liver

Abstract

HUNT, T. C., and ROWLEY, A. F. 1986. Studies on the reticuloendothelial system of the dogfish Scyliorhinus canicula. Endocytic activity of fixed cells in the spleen and liver. Can. J. Zool. 65: 1759-1769. The role of the spleen and liver of the lesser spotted dogfish, Scyliorhinus canicula, in the clearance of a range of materials, including colloidal carbon, latex beads, sheep red blood cells, bacteria, and dextran, was examined. The spleen was particularly important in the clearance process. Smaller particulates, such as carbon, were sequestered by the highly endocytic macrophages of the ellipsoids, while larger particles, for example, bacteria and sheep red blood cells, were mainly taken up by the fixed macrophages of the red pulp. An increase in the numbers of the eosinophilic G 1 granulocytes in the red pulp of the spleen was observed following injection of the particulates. In the liver, fixed cells, probably homologous to mammalian Kupffer cells, were involved in clearance and participated in endocytosis of carbon and latex. Additionally, all of the injected particulates were internalized by cells (frequently seen to also contain melanin granules) lying within nonsinusoidal blood vessels in the hepatic parenchyma. Often, but especially in fish injected with bacteria, these phagocytic cells appeared trapped along with free bacteria, within large clumps of circulatory blood cells in the vessels. The presence of the injected materials in the spleen and liver was evident at 30 min and increased up to 1 week. The ultimate localization and differential uptake of the injected materials, and the relative importance of the spleen and liver in the clearance of these materials are discussed.HUNT, T. C., et ROWLEY, A. F. 1986. Studies on the reticuloendothelial system of the dogfish Scyliorhinus canicula. Endocytic activity of fixed cells in the spleen and liver. Can. J. Zool. 65 : 1759-1769. Le r61e de la rate et du foie dans la clearance mdtabolique d'un certain nombre de substances (carbone colloi'dal, billes de latex, Crythrocytes de moutons, bactCries, dextran), a Ct C examink chez le requin Scyliorhinus canicula. La rate joue un r61e particulierement important dans le processus. Les particules plus fines, particules de carbone par exemple, sont sCquestrCes par les macrophages des ellipsoi'des qui assurent une endocytose efficace, alors que les particules plus grosses, bactCries et Crythrocytes de mouton par exemple, sont absorbdes surtout par les macrophages fixes de la pulpe rouge. On remarque une augmentation du nombre de granulocytes Cosinophiles GI dans la pulpe rouge de la rate apres injection des particules. Dans le foie, des cellules fixes, probablement homologues des cellules de Kupffer des mammiferes, jouent un r61e dans la clearance et elles assurent I'endocytose du carbone et du latex. De plus, tous les types de particules injectCes sont Cgalement sCquestrCs par des cellules (qui contiennent aussi souvent des granules de mClanine) situCes dans les vaisseaux sanguins (pas dans les sinusoi'des) du paren...

Ultrastructure of the Spleen and Head Kidney of Striped Bass

“…The spleen and head kidney are important in the immimological defense mechanisms and hematopoiesis offish (Ellis et al 1976;Ellis 1980;Secombes and Manning 1980;Tatner et al 1984;Lamers 1986), but only a limited number of general studies of the ultrastructure of these organs have been reported (Clawson et al 1966;Bielek 1981;Zapata 1981Zapata , 1982Pulsford et al 1982;Ishizeki et al 1984;Temmink and Bayne 1987). Other ultrastructural investigations offish spleens and head kidneys have limited their focus to the reticuloendothelial system (Graf and Schluns 1979;Ferguson 1984;Fulop and McMUlan 1984;Page and Rowley 1984;Hunt and Rowley 1986). Except for Groman's (1982) brief light microscopic study, the cytology of the hematopoietic tissues in the spleen and head kidney of striped bass Morone saxatilis is, to the best of our knowledge, unstudied.…”

The thromboxane mimetic, U‐46619, induces the aggregation of fish thrombocytes

“…Finally, of some significance is the observation of phagocytic activity of trout thrombocytes. Previous studies with dogfish, Scyliorhinus canicula (a cartilaginous shark-like fish), have shown that thrombocytes are apparently avidly phagocytic in vivo (Hunt & Rowley, 1986), but their initial in vitro experiments using bacteria as test particles failed to observe any significant amount of uptake by these cells compared with granulocytes and monocytes that were highly phagocytic. The thrombocytes of other vertebrates including birds are also thought to be phagocytic (e.g.…”

“…Previous studies with dogfish, Scyliorhinus canicula (a cartilaginous shark-like fish), have shown that thrombocytes are apparently avidly phagocytic in vivo (Hunt & Rowley, 1986), but their initial in vitro experiments using bacteria as test particles failed to observe any significant amount of uptake by these cells compared with granulocytes and monocytes that were highly phagocytic. Previous studies with dogfish, Scyliorhinus canicula (a cartilaginous shark-like fish), have shown that thrombocytes are apparently avidly phagocytic in vivo (Hunt & Rowley, 1986), but their initial in vitro experiments using bacteria as test particles failed to observe any significant amount of uptake by these cells compared with granulocytes and monocytes that were highly phagocytic.…”

Ligula intestinalis (L.) (Cestoda: Pseudophyllidea): plerocercoid‐induced changes in the spleen and pronephros of roach, Rutilus rutilus (L.), and gudgeon, Gobio gobio (L.)

“…In goldfish spleen, Dykova & Lom (1 979) observed endothelial cell swelling in response to infection with the haemoflagellate Trypanoplasma borelli. Studies using injected bacteria or inert particles have revealed the involvement of endothelial cells and associated macrophages in antigen-trapping in fish, although there is disagreement concerning the phagocytic capability of endothelial cells (e.g., Ellis, 1980;MacArthur et al, 1983;Hunt & Rowley, 1986). Phagocytosis of neutrophils by endothelial cells in ligulosed gudgeon pronephros was observed.…”