Comparative transmission electron microscopic studies on eosinophil of non ruminants

Transmission electron microscopic studies of eosinophil of horse, dog, pig and rabbit were carried out on six apparently healthy animals of each species. Ultrastructurally the eosinophils appeared round to oval in shape with few, short and narrow cytoplasmic processes in horse, oval with numerous long and wide cytoplasmic processes in dog and round with thin and broad small cytoplasmic processes in pig. While in rabbit it was round to oval in shape with long cytoplasmic processes. The nucleus had two to three lobes in all the animals. In all the four species it was observed that the heterochromatin was concentrated towards the periphery. Granules were mostly oval in outline and more or less similar in shape and size in horse while in dog the granules were rounded in shape and medium sized. In pig the double membrane bound cytoplasmic granules were roughly rounded to oval in shape and distributed throughout the cytoplasm. The granules in rabbit were mostly oval in outline and more or less similar in dimension. Cell organelles were clearly visible in the cytoplasm of horse while poorly visible in dog, pig and rabbit.