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Parathyroid glands from inbred rats were transplanted to rats of the same strain. The transplantation resulted in hyperparathyroidism and persistent hypercalcaemia. These hypercalcaemic animals were compared with the hypocalcaemic donors and with untreated controls. No significant differences in serum gastrin values were found between the different groups. In all three groups, one series of animals was killed 6 weeks after the transplantation (6w series) and another after 14 weeks (14w series). Quantitative studies of the antral gastrin cells showed an increase in the number of these cells per unit volume in the 6w series in the hyperparathyroid recipient animals. The number of gastrin cells per unit segment was also higher in the recipient animals than in the parathyroidectomized and untreated groups in both the 6w and 14w series. The amount of gastrin extracted from antral mucosa did not differ between the different groups. The findings show that an experimentally induced hyperparathyroidism in the rat gives a transient increase in the number of antral gastrin cells but no changes in the antral gastrin or serum gastrin levels.

The amount of gastrin-like immunostaining in gastrin (G) cells of the antral mucosa was quantified using a computer-assisted method of measuring immunoreaction product. Biopsies from 2 5 patients without Heliobacter-like organisms and 60 patients with varying degrees of infection were immunostained for gastrin. Twenty-five G cells from each patient were measured both subjectively and by image analysis. Gastrin-like immunoreactivity was found to be significantly increased in the presence of Heliobacter-like organisms.

SUMMARY Background: The aim of this study was to compare omeprazole 10 mg o.m. (daily) with omeprazole 20 mg o.m. on Friday to Sunday inclusive (weekend) in the prevention of duodenal ulcer relapse over a 6-month period. Methods: After an open healing phase (4 to 8 weeks) with omeprazole 20 mg o.m., 81 patients entered the follow-up phase. Forty-two were randomized in a double-blind double-dummy technique, to omeprazole 10 mg o.m., and 39 to omeprazole 20 mg at weekends, At 3 and 6 months or on symptomatic relapse the patients underwent endoscopy with gastric biopsies (quantitative assessment of argyrophilic and gastrin cells), symptom evaluation, and laboratory screening with fasting serum gastrin. Results: Five patients in the 10 mg group and four in the weekend group were lost to follow-up. The estimated relapse rates over six months in the two groups receiving 10 mg daily or 20 mg at weekends were 19% and 31%, respectively (95% CI of percentage difference: –33% to 8%; intention-to-treat analysis, P = N.S.). During the follow-up phase, symptoms tended to be milder in the omeprazole 10 mg daily group compared to the weekend group. Gastrin levels increased significantly during the healing phase but then stayed almost constant in the omeprazole 10 mg group, and significantly decreased with weekend treatment. The median number of argyrophilic cells showed a slight but statistically significant increase in the omeprazole 10 mg daily group, but did not change in the weekend group. Both the healing and long-term therapies were well tolerated. Conclusions: Our data do not show a clear difference between the two treatment regimens, but there was a tendency towards a lower recurrence rate with omeprazole 10 mg daily compared with 20 mg weekend therapy.

Using immunoperoxidase technique a considerable variation in the number of antral gastrin cells was demonstrated in patients with atrophic gastritis. This variation must be taken in consideration when the number of gastrin cells is to be estimated on the basis of gastric biopsies.

We studied the acute effect of transthoracic truncal vagotomy or sham vagotomy (control) on fasting serum gastrin concentrations in 22 gastric fistula dogs. A significant (p less than 0.05) decrease in serum gastrin concentration was detectable within 2.5 minutes after truncal vagotomy, and by 120 minutes serum gastrin has decreased to 15 +/- 1 pg/mL in the vagotomy group compared to 28 +/- 3 pg/mL in the control group (p less than 0.001). However by 24 hours after vagotomy, when maximal acid output was reduced by approximately 50%, fasting serum gastrin had increased nearly twofold above control levels in the vagotomy group (p = 0.06) and this increase persisted at day 7 (p less than 0.05). Thus truncal vagotomy had a biphasic effect on serum gastrin concentrations in dogs (acute inhibition followed by stimulation). While the mechanism for the acute fall in gastrin is probably an acute denervation of postganglionic neurons that innervate gastrin cells, the mechanism for the subsequent rise in serum gastrin remains uncertain.

Fixation of fragments of human antral mucosa with Helly's fluid allows gastrin-containing cells to be identified by an immunofluorescence technique. Lead-Haematoxylin staining carried out on the same sections shows selective reactivity of the immunofluorescent cells. These findings support the identification of gastrin cells with G cells, known from previous studies to react with lead-Haematoxylin.

The origin and renewal of the gastrin cells in the pyloric glands of hamsters were studied by [ 3 H]thymidine autoradiography combined with the immunoperoxidase identification technique. After a single injection of [ 3 H]thymidine, the labeling index of gastrin cells was 0.3%, indicating that a few gastrin cells at the isthmus region have a self-replicating activity. Following pulse labeling after five repeated injections of [ 3 H]thymidine at 6-hr intervals, the labeling index of the gastrin cells showed a linear increase (from 1.2% on the 1st day to 5.2% on the 4th day), and attained a plateau (5.6%) on the 5th day. These findings indicate that most gastrin cells differentiate functionally within 5 days. On the 5th day after the last of 41 injections repeated at 6-hr intervals, the labeling index of gastrin cells was 25.8%, and it decreased gradually as follows: 22.3%, 18.3%, 11.2%, 7.3%, 0.9%, and 0% on the 10th, 15th, 20th, 30th, 50th, and 100th day, respectively. From analysis of this decreasing curve, the turnover time of the gastrin cells (a half-life of the cells) was estimated to be 10–15 days. Spatially, the labeled gastrin cells were at first found in a region from the isthmus to the upper level of the glands and later in the lower level of the glands. This indicates that the gastrin cells arising from immature precursor cells at the isthmus region migrate downwards toward the bottom of the glands.

The gastrin-producing cells in the cat have been studied under various experimental conditions indicating the secretory cycle of these cells. Normal gastrin cells in animals fed ad libitum show secretory granules of different electron density. After fasting for 24 hrs the cells are granulated with electron dense secretory granules and after refeeding the cells are degranulated, showing clear secretory granules. The implication of the endoplasmic reticulum and the Golgi apparatus in the secretory cycle is discussed on the basis of the ultrastructural findings.

In the pyloric antrum of dog and pig it is possible to show, by direct re-staining of formaldehyde-fixed sections after localization of the gastrin cells by immunofluorescence, that these cells are identical with the argyrophilic, lead haematoxylin-positive G cells.

A case of malignant endocrine tumour of the jejunum, associated with severe duodenal ulcer is described. The tumour and a local metastasis were examined by immunohistochemistry and found to contain abundant somatostatin-immunoreactive cells together with less numerous cells displaying gastrin immunoreactivity. This is to our knowledge the first case of intestinal somatostatinoma. The presence of gastrin cells in the tumour may explain the ulcer diathesis.

Growth hormone (GH)-immunoreactive material was found to occur in the antral gastrin cells and in scattered cells of the pancreatic islets in several mammalian species, including man. Examination of gastrinomas revealed the majority of tumour cells to display GH-like immunoreactivity.

A simple technique has been developed to quantitate the gastrin cells (G-cells) from the pyloric antrum of the rat. The antrum was digested in pronase to suspend the epithelial cells. This cell suspension was counted and pelleted. The pellet was embedded in paraffin, sectioned, then labeled using the indirect immunofluorescence technique specific for gastrin. The percentage of G-cells was determined from photographs of fluorescing sections and total G-cell numbers were determined by relating these data to total epithelial cell counts. In 14 rats the average G-cell population totaled 1.03 +/- 0.21 X 10(5) G-cells/antrum. The technique is simple, time-saving and avoids the uncertainties inherent in previous procedures for the estimation of G-cell numbers.

Gastrin cells in the pigeon, quail, gull and kite were identified at ultrastructural level by immunocytochemistry, using the consecutive semithin/ultrathin section technique. In contrast to the gastrin granules known in mammals, the avian gastrin granules generally contained a consistent dense core accompanied by a clear halo between the core and limiting membrane. The mean diameters of gastrin granules in the pigeon, quail, gull and kite were 211 +/- 37, 247 +/- 45, 331 +/- 61 and 353 +/- 73 nm respectively. The carnivorous birds seemed to possess larger gastrin granules than the grain-eating birds. The species differences in the size and fine structures of the gastrin granules were discussed.

Nineteen rats were parathyroidectomized by electrocauterization, resulting in pronounced hypocalcaemia. Seven of these rats were then given vitamin D3 in a dose causing hypercalcaemia, while 7 received a dose which normalized serum calcium and 5 received no vitamin D. Ten further animals were sham-operated and were not given any extra vitamin D. The experimental period was 16 weeks. No significant differences in serum gastrin values were found between the different groups. Quantitative studies of the antral gastrin cells showed no difference in the number of gastrin cells per unit volume or unit segment between the different groups of vitamin-D-treated animals and sham-operated animals. However, the number of gastrin cells per unit segment was significantly higher in the hypocalcaemic animals than in the sham-operated animals, as a result of an increase in mucosal thickness. The amount of antral mucosal gastrin did not differ between the different groups. Thus the results of this study indicate that experimentally induced hypercalcaemia in parathyroidectomized rats does not influence the serum gastrin, the number of gastrin cells or antral gastrin.

Region-specific antisera to three enkephalins: met-enkephalin, met-enkephalin-Arg6-Phe7 and met-enkephalin-Arg6-Gly7-Leu8, together with four region specific antisera to progastrin: C-terminal G17 specific, N-terminal G34 specific, cryptic peptides A- and B-specific, were used in immunohistochemical studies of hog antral mucosa. A sub-population (6–10%) of the gastrin-containing endocrine cells (G-cells) was found to react with antisera to met-enkephalin, met-enkephalin-Arg6-Phe7 and met-enkephalin-Arg6-Gly7-Leu8. About 30% of all the enkephalin-containing cells were identified as G-cells. The results indicate that a fraction of G-cells produces both enkephalin-like peptides and gastrin.

The distribution of gastrin immunoreactivity in the rat gut was examined by immunochemical and immunohistochemical techniques. Gastrin occurs predominantly in the antrum proper, but gastrin is found also in the adjacent part of the oxyntic mucosa and in the duodenum. In the remainder of the gut the gastrin concentration is very low. No gastrin cells and very low gastrin concentrations are observed in the antrum at birth. The gastrin concentration as well as the number of gastrin cells increases progressively with age. The antral gastrin concentration reaches adult or near-adult values 30–40 days after birth.

Examination of human gastric biopsies by an indirect immunofluorescence technique using antihuman gastrin confirms the variability in distribution and number of gastrin-secreting (G) cells (Solcia, Vassallo, and Capella, 1969) observed by morphological, cytochemical, and electron microscopical studies. In cases with presumed secondary hypersecretion a profound degree of G-cell hyperplasia is observed. Immunofluorescence with. antigastrin can provide valuable information on the state of the G cells in different physiological states, particularly if used in conjunction with other cytochemical techniques.

To solve the unsettled problem of the identification of the gastrin cells, a study has been undertaken on the electron microscopical characteristics of the gastrin-containing cells of the cat pyloric mucosa. Cells which, on semithin sections, were shown by an immunofluorescence method to contain gastrin, have been identified on serial ultrathin sections. The ultrastructural features of these cells are those which have been described as characteristic of the G cells of the antropyloric mucosa. Other non-entero-chromaffin endocrine cells, which have been recognized as the D cells of the gastro-intestinal mucosa, did not result to contain gastrin.