Gastrin stimulates the growth of gastric pit cell precursors by inducing its own receptors.
Gastrin/CCK-B receptors (CCKB-Rs) are present on parietal and enterochromaffin-like cells in the gastric mucosa but not on pit cells in the proliferative zone. Because serum gastrin levels are well correlated with the growth of the gastric pit, we examined whether pit precursor cells express CCKB-Rs using hypergastrinemic transgenic mice and a mouse pit precursor cell line, GSM06. In situ hybridization indicated that CCKB-R mRNA was limited to the lower one-third of the mucosa in control mice, whereas it was faintly distributed along the mid- to low glandular region in the hypergastrinemic transgenic mouse mucosa. CCKB-R-positive midglandular cells appear to have a pit cell lineage; therefore, GSM06 cells were used for an [(125)I]gastrin binding study. [(125)I]gastrin bound to the membrane fraction of the GSM06 cells when precultured with gastrin. Gastrin dose dependently induced CCKB-R expression in GSM06 cells and stimulated their growth. Thus these findings suggest that gastrin directly stimulates the growth of the pit cell lineage by inducing its own receptor in pit cell precursors.
Nakajima
Toshio
T
Department of Gastroenterology and Hepatology, Kyoto University Graduate School of Medicine, Kyoto 606-8507, Japan.
Konda
Yoshitaka
Y
Izumi
Yoshio
Y
Kanai
Masashi
M
Hayashi
Naoki
N
Chiba
Tsutomu
T
Takeuchi
Toshiyuki
T
D000595:Amino Acid Sequence; D000818:Animals; D002455:Cell Division / Q000187:drug effects / Q000502:physiology; D005753:Gastric Mucosa / Q000473:pathology* / Q000502:physiology; D005755:Gastrins / Q000235:genetics* / Q000378:metabolism / Q000494:pharmacology; D005756:Gastritis / Q000473:pathology* / Q000503:physiopathology; D015870:Gene Expression / Q000502:physiology; D006984:Hypertrophy; D017403:In Situ Hybridization; D007457:Iodine Radioisotopes; D051379:Mice; D008813:Mice, Inbred ICR; D008822:Mice, Transgenic; D008969:Molecular Sequence Data; D012333:RNA, Messenger / Q000032:analysis; D043887:Receptor, Cholecystokinin B; D011949:Receptors, Cholecystokinin / Q000235:genetics*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012844:Sincalide / Q000494:pharmacology; D013234:Stem Cells / Q000166:cytology*
D005755:Gastrins; D007457:Iodine Radioisotopes; D012333:RNA, Messenger; D043887:Receptor, Cholecystokinin B; D011949:Receptors, Cholecystokinin; D012844:Sincalide