Incorporation of human chorionic gonadotropin alpha-subunit into different types of granule in stomach endocrine cells. An immunoelectron microscopic study.

In order to demonstrate the ultrastructural localization of the alpha-subunit of human chorionic gonadotropin (hCG) in the stomach mucosa, an immunoelectron microscopic study was performed using formalin-fixed specimens. In pyloric glands, alpha hCG-positive granules were irregular in outline, with a mean area and maximum diameter of 2,857 x 10(4) nm2 and 218.4 nm, respectively. In fundic glands, the granules had a smoother outline and were larger in both area and maximum diameter (3,943 x 10(4) nm2, 246.8 nm) than those of pyloric glands (p less than 0.001). In the atrophic fundic glands of non-antral gastritis, the alpha hCG granules showed a difference in shape; more elliptical granules appeared to be increased, as indicated by the higher value of the axial ratio (1,452) and lower value of D (1,862) (log10 area alpha D.log10 perimeter) compared with those in pyloric (1,231, 1,968) and fundic glands (1,148, 1,979) (p less than 0.001). The alpha-subunit of hCG is thus incorporated into different types of endocrine cell in pyloric and fundic glands, and the granule morphology appears to differ in hyperplastic alpha hCG cells of non-antral gastritis.