The intestinal gland of Trichinella spiralis with emphasis on morphology and antigenicity.

The intestinal gland of muscle larvae and adult worms of Trichinella spiralis was investigated with emphasis on its morphology and antigenicity. The gland is situated at the junction between the stichosome and the ampullar portion of the midgut. The cytoplasm was characterized by the presence of cytoplasmic granules. The granules, measuring 1 micron at maximum, were round or sometimes irregular in shape, and of homogeneous appearance with medium to high electron density. Rough endoplasmic reticulum was not prominent. Glycogen granules were absent. The gland was surrounded externally by the basal lamina and hemolymph. The cell membrane was extensively invaginated, and coated pits and vesicles were often observed. The cytoplasm was rather eosinophilic, PAS-negative, and stained red or yellow by AZAN. The cytoplasmic granules were antigenic against trichinosis sera from humans and rats, and cross-reacted with sera from paragonimiasis, trichuriasis and gnathostomiasis patients.