Histological and histochemical study of the hepatopancreas freshwater cray fish (Astacus leptodactylus)

In this study, 40 adult live, crayfish (Astacus leptodactylus) of Aras dam was prepared. After oral administration of 10% formalin and remove cuticular cover, they kept in formalin 10%. Then tissue sections were prepared using standard methods. The tissue sections were stained by H&E, PAS, Alcian blue, Von Kossa and Masson's trichrome and examined under a light microscope. Results showed that the hepatopancreas is covered by a thin capsule of connective tissue from outside and tubular glands are complex which in cross-section, these tubes have a star-shaped channel consists of a row from pyramidal to cylindrical cells which contains filamentous cells with basophilic cytoplasm and euchromatin nucleus (Fibrillar cell) and secretive cells including cytoplasm filled with vacuolated secretions and euchromatin nucleus. Density of secreting cells in the lining glands is more than filamentous cells which all are placed on a basement membrane. Secretions in cytoplasm of secretary cells were non-carbohydrate compounds and connective tissue were of loose connective tissue. Also there are calcium compounds in the cytoplasm of parietal cells of glands which concentration of these compounds in filamentous cells reaches to its maximum. In general it can be said that hepatopancreas have different cells with different tasks that some of them such as S cells that secrete enzymes and F cells that may be the site for endocytosis. Also cells containing large amounts of calcium can be named as R cells that will have special role in calcium storage and use of it during biological cycles such as molting.