Proliferation and functional changes of pancreatic gastrin cells in neonatal rat.

INTRODUCTION: Although gastrin cells are not found in the adult pancreas, they are found transiently in the neonatal pancreas. It has been suggested that gastrin may play a role in pancreatic development. However, cell kinetics as well as the fate and the role of gastrin cells are not clear. METHODOLOGY: Proliferation and functional changes of pancreatic gastrin cells in neonatal Wister rats were studied by immunohistochemistry and [(3)H]thymidine autoradiography. RESULTS: Numbers of pancreatic gastrin cells in neonatal rats showed a peak immediately after birth and then decreased rapidly. Gastrin cells were observed within approximately 2 weeks after birth in islets and within approximately 4 weeks after birth among exocrine cells. In contrast with the decrease of gastrin cell numbers, numbers of duodenal cholecystokinin cells increased remarkably after 7 days of age. Proliferative activity of acinar cells showed two peaks at age 2 days and 9 days. Despite a decrease in gastrin cell numbers, gastrin cells maintained a certain degree of proliferative activity. The "re-staining method" for gastrin and insulin revealed that immunoreactive cells for both gastrin and insulin were rarely found a few days after birth. CONCLUSION: These results suggest that pancreatic gastrin cells do not die off or change to another type of endocrine cell and that some gastrin cells change to insulin cells.

A case of hemangioma accompanied by inflammatory pseudotumor of the spleen.

Both hemangioma and inflammatory pseudotumor (IPT) of the spleen are rare benign mass lesions. Moreover, a splenic hemangioma accompanied by IPT is extremely rare. A 61-year-old woman who suffered from liver cirrhosis had a splenic cavernous hemangioma surrounded by granuloma. The literature on IPT of the spleen has described several possibilities of its causes; however, it is still unknown. This case was accompanied by portal hypertension due to liver cirrhosis, which may cause microrupture of hemangioma resulting in an IPT.

Carboxyl terminal glycine extended progastrin (gastrin-G) in gastric antral mucosa of patients with gastric or duodenal ulcer and in gastrinomas.

Recently, carboxyl terminal glycine extended progastrin (gastrin-G), the immediate biosynthetic precursor of amidated gastrin, was found in human gastric antral mucosa. To investigate in pathophysiological conditions, we examined gastrin and gastrin-G levels and their molecular forms in gastric antral mucosa of healthy controls and patients with gastric or duodenal ulcer and in gastrinomas. There were no significant differences between controls and gastric or duodenal ulcer patients in antral gastrin and gastrin-G levels, the ratio of gastrin-G to gastrin and the pattern of their molecular forms. In contrast, gastrin and gastrin-G levels and the ratio of gastrin-G to gastrin in gastrinomas were much higher than those in antral mucosa of controls or ulcer patients. The predominant molecular form of gastrin-G was different between two Zollinger-Ellison syndrome (ZES) cases. These results suggest that there are no significant differences between healthy controls and patients with gastric or duodenal ulcer in the nature of gastrin amidation, and that the nature of gastrin amination in gastrinomas is different from that in normal gastrointestinal tissues.

[The effect of sofalcone on the kinetics of the generative cells and superficial epithelial cells in mouse gastric mucosa].

Effects of an anti-ulcer drug, 2'-carboxymethoxy-4,4'-bis(3-methyl-2-butenyloxy) chalcone (sofalcone), on the generative cells and kinetics of superficial epithelial cells in mouse gastric mucosa, including the effect of hydrocortisone on them, were investigated by the use of 3H-thymidine autoradiography. The labeling indices and the width of the generative cell zone in the fundic mucosa were significantly decreased by administration of hydrocortisone. The decrease in the labeling indices and the width of the generative cell zone induced by administration of hydrocortisone were not inhibited by sofalcone. Hydrocortisone had no significant influence on the labeling indices of the generative cell zone in the pyloric mucosa, but decreased the width of it. The decrease in the width of the generative cell zone induced by hydrocortisone was inhibited by sofalcone. Concerning the influence on the kinetics of superficial epithelial cells, hydrocortisone inhibited the increase in the labeling indices of the superficial epithelial cells after continuous administration of 3H-thymidine in both the fundic mucosa and pyloric mucosa. In the fundic mucosa, sofalcone showed no influence on the inhibition by hydrocortisone, but in the pyloric mucosa, the effect of hydrocortisone was abolished by sofalcone. These results suggest that sofalcone inhibits the reduction of the cell production and the prolongation of the life span of superficial epithelial cells caused by hydrocortisone in the pyloric mucosa.

[Ontogeny of pancreatic gastrin cells in neonatal rat].

It is well known that gastrin immunoreactive cells are observed in the fetal and postnatal rat pancreas. The role of the gastrin cells is unknown, however, it has been suspected that pancreatic gastrin may influence the development of pancreas and the gastrointestinal tract. The present study shows the localization of pancreatic gastrin cells and the ability of auto-proliferation of them in development. Gastrin cells were seen in 0-d to 2-wk-old rats in islet and in 0-d to 4-wk-old rats among exocrine cells. The ratio of gastrin cells to islet cells decreased in neonatal development and in rats older than 14-d gastrin cells were never observed in islet. Labeling indices of pancreatic gastrin cells after one injection of tritiated thymidine were 2.6% to 4.6% for 10 days after birth. It was suggested that gastrin cells have the ability of autoproliferation for 10 days after birth.

[The effect of chemical sympathectomy on the cell kinetics of gastric mucosa in golden hamsters].

The effects of chemical sympathectomy on the differentiation of the generative cells, superficial epithelial cells and gastrin cells of the gastric mucosa of hamster were examined by 3H-thymidine autoradiography. The labeling indices of the generative cell zone in the gastric mucosa and antral gastrin cells showed a transient significant decrease after chemical sympathectomy, and then they were gradually restore with time. After 4 weeks onward, the labeling indices of the generative cells showed a slightly low value compared with those in controls. The renewal of superficial epithelial cells and gastrin cells was examined in the hamster sympathectomized for 4 weeks. The time required for the differentiation to PAS positive superficial epithelial cells or gastrin cells had a tendency to elogate after chemical sympathectomy. These results suggest that chemical sympathectomy played an inhibitive action on the proliferation and the differentiation of gastric mucosa.