Effect of parathyroid hormone on gastrin and somatostatin release from the gastric antrum

The release of immunoreactive gastrin and somatostatin form the gastric antrum was studied in anesthetized pigs after parathyroid hormone (PTH) infusion into the antral circulation. PTH (40 units/20 min) was infused into the right gastro-epiploic artery. Blood was sampled from the right gastro-epiploic vein (antral venous blood) and from the superior vena cava (mixed venous blood). The basal gastrin concentration in antral venous blood was 17 times higher than that in mixed venous blood (1220 + 367 versus 71 +25 pmol/1, mean +SE). The somatostatin concentrations in antral and mixed venous blood were 127 +20 and 82 +23 pg/ml (mean +SE), respectively. After PTH infusion the gastrin level both in antral and mixed venous blood increased significantly without inducing systemic hypercalcemia. PTH infusion did not significantly influence the somatostatin level either in antral venous blood or in mixed venous blood. The findings demonstrate that PTH can induce gastrin release from the gastric antrum without concomitant systemic hypercalcemia and that this release of gastrin is not accompanied by a change in the somatostatin level in antral venous blood.