Five types of nuclei present in the capsule of Trichinella spiralis

This study describes morphological changes during capsule formation of Tric hinella spiralis with emphasis on nuclei within the capsule. The nuclei of the pre-existing muscle cell may become hypertrophied or degrade soon after the entrance of newborn larvae. Cytoplasm associated with these hypertroph ied nuclei was basophilic in H&E staining and composed of mitochondria and rough endoplasmic reticulum. Satellite cells underwent cell division and jo ined to the nurse cell. These nuclei may also become hypertrophied or degra de. Cytoplasm associated with nuclei of satellite cell origin was eosinophi lic in H&E staining and composed of mitochondria, polysomes, and smooth and rough endoplasmic reticulum. Eosinophilic cytoplasm (of satellite cell ori gin) became prevalent in the capsule as capsule formation proceeded. Infilt rated cells were observed within the capsule. Thus this study showed divers ity of nuclei in the capsule of Trichinella.