Ultrastructural observations on the granulocytic leucocytes of the teleost Catostomus commersoni.

Abstract

Leucocytes from the blood and inflammatory tissues of C. commersoni were examined with the electron microscope. Neutrophils in sections of blood were recognized by their lobed nucleus and numerous irregularly shaped granules approximately 0.5 μm in diameter. Many of the granules had electron-dense inclusions. Eosinophils were characterized by a compact eccentric nucleus and oval, uniformly electron-dense granules measuring 0.8 μm in diameter. Cells tentatively classed as basophils had a lobed nucleus and spherical, uniformly electron-dense granules about 0.75 μm in diameter.Inflammatory tissue produced within 24 h of making a small incision contained numerous neutrophils and eosinophils. Many of the eosinophils were "degranulating." Their granules were enlarged and contained both electron-dense and electron-lucid areas. Some granules had apparently coalesced and others, presumably at a later stage in degranulation, had lost the granule membrane. Intact cells filled with granule-derived material were observed.