MORPHOMETRY OF GASTRIC ENDOCRINE-CELLS IN HYPERGASTRINEMIC PATIENTS TREATED WITH THE SOMATOSTATIN ANALOG OCTREOTIDE

The aim of the study was to evaluate whether treatment with 200 mug/d of the somatostatin analogue octreotide (SMS 201-995) for three months can influence the trophic action exerted by hypergastrinemia on endoc rine cells of the oxyntic mucosa, a condition potentially leading to h yperplasia and carcinoid tumors. Endocrine cells were morphometrically investigated in Grimelius silver stained sections of endoscopic biops ies of oxyntic mucosa collected from 13 hypergastrinemic patients with Zollinger-Ellison syndrome (ZES) (n = 5), antral G cell hyperfunction (AGCH) (n = 4) and atrophic gastritis type A (AG-A) (n = 4) before an d after 3 months treatment and 3 months after drug discontinuance. The treatment induced a reduction of the volume density (P<0.015), profil e cross sectional area (P<0.05) and number of cell profiles per unit a rea (P<0.015) of argyrophil cells. A rebound of all these parameters w as observed 3 months after drug withdrawal with values usually exceedi ng those at the entry, except in cases of AG-A. The patients' plasma g astrin concentrations presented similar variations showing a significa nt relation with all morphometric parameters of argyrophil cells. Also , the cell content in alpha subunit of human chorionic gonadotropin wa s related to the plasma gastrin levels, a finding confirming the close gastrin dependence of the expression of this protein by oxyntic endoc rine cells. No significant changes were observed in mucosal somatostat in D cells. These results indicate that variations in circulating gast rin levels are the most likely factor responsible for the hypotrophic effect of octreotide on oxyntic argyrophil cells (mostly corresponding to the ECL cells) of hypergastrinemic patients.