ANTRAL GASTRIN CELL-POPULATION IN PATIENTS WITH CHAGASIC MEGAESOPHAGUS AND MEGACOLON

1. Patients with chronic Chagas' disease have abnormally low gastric a cid secretion and increased gastrin release both during fasting and af ter different stimuli. Regardless of the relationship between intragas tric acidity and gastrin secretion, it is uncertain whether hypergastr inemia in Chagas' disease is caused by an increased population of antr al gastrin (G) cells (hyperplasia) or by enhanced cell activity (hyper function). 2. We therefore estimated G cell number in antral biopsies from 16 chagasic patients and 13 control subjects using a peroxidase-a nti-peroxidase immunohistochemical technique. All subjects underwent a gastric secretion test to determine peak acid output following intrav enous pentagastrin instillation. 3. Antral G cell number in Chagas' di sease patients was not significantly different from that observed in t he control group (number of cells/mm(2), median and (range): 128 (44-2 84) vs 138 (65-285)). 4. In chagasic patients, peak acid output was si gnificantly lower than in controls (mmol/h, median and (range): 9.819 (3.024-21.564) vs 17.490 (9.423-25.848)). 5. These results suggest tha t the increase in gastrin release associated with reduced gastric acid secretion in Chagas' disease is mediated by antral G cell hyperfuncti on rather than by hyperplasia.