Adenylate cyclase in human gastric mucosa: its activation by histamine in morphologically different biopsy specimens

Abstract

In morphologically different biopsy specimens from fundic, antral and duodenal mucosa of 134 persons, basal and histamine stimulated adenylate cyclase activity was studied: Basal and stimulated adenylate cyclase activities were log-normally distributed. Only in the fundic but not in the antral and duodenal mucosa adenylate cyclase was sensitive to histamine. The mean basal activity in the fundic gastric mucosa was 148, in response to 10(-5) mol/l histamine 292 pmol cAMP/mg protein/20 min. In human fundic biopsy specimens histologically identified as normal gastric mucosa, the stimulatory effect of histamine on adenylate cyclase decreased with the individual's age. In bioptic material from patients suffering from histologically proven chronic gastritis the histamine effect decreased with the degree of atrophy. A similar loss of histamine sensitivity was found in gastric mucosal biopsies of antrectomized individuals operated at least 5 years before by the Billroth I or II method, whereas in the mucosa of patients with gastric or duodenal ulcer no loss occurred. In contrast, the most pronounced stimulatory action of histamine was found in this latter group. Since a histamine sensitive adenylate cyclase is localized only in the glandular area of the fundic mucosa and the histamine sensitivity depends on a morphological intact structure of the mucosa, it can be concluded, that the effects of histamine on adenylate cyclase and on hydrochloric acid acid secretion have to be considered as a mechanism linked together.

Morphologically Different Biopsy Specimens of the Human Gastric Mucosa

“…This investigation has shown that basal, PGE2-and histamine-stimulated AC activi ties are log-normally distributed, so confirm ing earlier findings [3].…”

“…Two were used for histological examination and the third one for estimation of AC activity. This sam ple was placed in an Eppendorf vial and stored at -2 0 °C until required [3). The patients were divided into 7 groups according to histological or clinical diag nosis.…”

“…In former studies [3,4] we investigated the degree of AC activation by a single histamine concentration in biopsies of normal human gastric mucosa and patients with chronic su perficial gastritis (GI). chronic gastritis with beginning atrophy (GII), chronic atrophic gastritis (Gill), gastric ulcer (GU), duodenal ulcer (DU), and Billroth II patients (BII) and found specific differences.…”

Biomarkers in Patients with Gastric Inflammation: A Systematic Review

“…Several studies indicated the relation between gastric inflammation and other markers including muscarinic receptors [59], adenylate cyclase [60], cell proliferation kinetics [61], anti-G cell antibody[57] and bacterial characteristics [62,63,64]. However, these markers have been discussed only in limited reports and have not been widely confirmed.…”

Morphologically Different Biopsy Specimens of the Human Gastric Mucosa

“…However, these tiny particles of sometimes less than 1 mg are also sufficient for biochemical investigations. In our studies on the regulation of human gastric mucosal adenylate cyclase [1][2][3], we have used biopsies and noticed that the inter pretation of the data on a pure histological basis, lacks sometimes information on the cellular composition of the biopsy, in partic ular on parietal cells. Thus, we looked for a method which would provide numerical data on parietal cells from single biopsies.…”