Intracellular topography of glycine-extended pro-gastrin-processing intermediates in human antral mucosa: an electron-microscopic immunocytochemical study.
To identify and characterize the subcellular topography of glycine-extended pro-gastrin-processing intermediates (G-Gly) in human antral mucosa, we performed an electron microscopic immunocytochemical study using region-specific antisera generated against the synthetic peptide, Tyr-Gly-Trp-Met-Asp-Phe-Gly (GL7), and C-terminal-specific anti-gastrin antisera. As has been previously reported, G-cells contained both electron-dense and electron-lucent granules, with a range of intermediate forms. Gastrin immunoreactivity was demonstrated in almost all granules of each type, whereas anti-GL7 antisera immunostained chiefly electron-dense granules. The relative ratio of GL7/gastrin granules varied among different cells but was approximately 1:10 on average. Other cytoplasmic organelles were devoid of specific labeling for GL7 or gastrin. As we have assumed that G-Gly serves as the immediate precursor for each molecular form of gastrin, electron-dense granules with high labeling for GL7 are regarded as the principal site for conversion of G-Gly to gastrin. This speculation supports many previous reports that electron-dense granules are immature and that the granules become less electron-dense with maturation.
Funata
N
N
Department of Pathology, Tokyo Metropolitan Komagome Hospital, Japan.
Fukayama
M
M
Sugano
K
K
Koike
M
M
D000328:Adult; D000595:Amino Acid Sequence; D003594:Cytoplasmic Granules / Q000032:analysis; D005260:Female; D005753:Gastric Mucosa / Q000032:analysis* / Q000648:ultrastructure; D005755:Gastrins / Q000032:analysis*; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D008854:Microscopy, Electron; D008875:Middle Aged; D008969:Molecular Sequence Data; D015388:Organelles / Q000032:analysis; D011706:Pyloric Antrum
D005755:Gastrins; C058638:tyrosyl-glycyl-tryptophyl-methionyl-aspartyl-phenylalanyl-glycine