Tez özetleri Astronomi ve Uzay Bilimleri Anabilim Dalı

A Structural Study Of Functional Cells In Hepatopancreas In Mytilus Galloprovincialis Lamarck, 1819.

The purpose of this study is to research the histology and the seasonal lipid content with activity of catalase of the hepatopancreas of Mytilus galloprovincialis Lamarck, 1819 by light microscope. Samples were collected from designed areas at Yenikapı shores in Marmara Sea between June 2004-June 2005. Using the histological methods, parafine blocks have been made from the parts of hepatopancreas that has been taken from collected the samples. The section with 5-6 µm of thickness which has been cut from the parafine blocks were stained with histological stains. Using the histochemical methods, lipid and catalase were also marked from the samples which were taken from the hepatopancreas. The hepatopancreas of Mytilus galloprovincialis is a complex organ composed of digestive tissue and connective tissue. The digestive tissue comprises of a series of blind ending tubules communicating with the stomach by sequence of the branching digestive ducts. There are two kinds of digestive ducts, primary ducts and secondary ducts. There are two different regions which surround the lumen of primary ducts. First region is comprised of ciliated epithelium which has form of a groove. This region transfers partially digested food particules from stomach to tubules. Second region is comprised of brush border epithelium which are ridges and furrows. This region transfers to stomach wastes of digestive products in hepatopancreas and secretion which produced by basophilic cells. Secondary ducts are composed of non-ciliated, brush border epithel tissue. Secondary ducts are open to the branching blind-ending tubules. The tubules epithelium are composed of columnar, acidophilic digestive cell and pyramidal basophilic secretory cell.

The connective tissue in hepatopancreas is consist of two different cells. From these, first is vesicular connective tissue (VCT) cells and second is adipogranular connective tissue (ADG) cells. The function of both VCT and ADG cells are storage of transfered particules to hepatopancreas. Adipogranular connective tissue cells store protein granules and lipid droplets while vesicular connective tissue cells store large amounts of glycogen in a single large vesicle in the cytoplasma. These storage materials constitute energy reserves, particularly for gametogenesis. Vessels and ameoboid blood cells (ameobocytes) are also present in both connective tissue.

In our study, by the exposure of the histological structure of the hepatopancreas of Mytilus galloprovincialis Lamarck, 1819 by light microscope, it has been concluded that under the influence of environmental and biotic factors, especially lipid as an energy reserve and activity of catalase related with the detoxification function are showing seasonal alterations. This study is thought to be base for future studies which are concern with digestion/assimilation and detoxification.