Duodenal and antral mucosal prostaglandin E2 synthesis in a study of normal subjects and all stages of duodenal ulcer disease treated by H2 receptor antagonists.

Abstract

Group (cl) ulcer rim made 49-8 (22.7) and at all stages ulcer rim and scar made less than the control duodenal bulb (p<002). Uninvolved duodenal bulb from groups (cl) (63-4 (31i0)), (c2) (83-6 (38 5)), and (c3) (81-5 (31-1)), however, also made significantly less than controls (p<002) and a similar though non-significant trend was seen in group (c4). Biopsies from the second part of the duodenum did not synthesise significantly less than the control group but a similar trend was noticed at each stage of ulcer treatment. Biopsies of control antrum synthesised 124-5 (32-2) but only 93 7 (44 2) in group (ci) (p<0005). All stages of duodenal ulcer healing were associated with a decreased capacity to synthesise the major prostaglandin PGE2 at the ulcer site and the uninvolved duodenal bulb and, in acute untreated duodenal ulcer, the uninvolved antrum. This decreased capacity may be the consequence of the disease process itself and not secondary to the treatment, indicating a basic pathophysiological abnormality which may explain the characteristic tendency of the disease to relapse.Animal work suggests that endogenous prosta-gastric and duodenal ulcer."'3 The majority of studies glandins may be a component of mucosal protection have looked at relatively few patients and methodoand rapid repair. I-3 Attempts to estimate mucosal logical problems may have failed to reveal a conprostaglandin synthesis in patients with peptic ulcera-sistent pattern. 14 None have looked at synthesis tion, however, has produced conflicting results in during the healing of peptic ulcers. In this study,

Duodenal ulcer prevalence: Experimental evidence for the possible role of dietary lipids

“…Prostaglandin (PG) E 2 synthesis was measured by using a radioimmunoassay (anti‐PGE 2 antibody; Sigma Chemicals, St Louis, MO, USA) by following the method described by Pugh et al 17 …”

Simultaneous Measurement of In Vitro Gastroduodenal Prostaglandin E2Synthesis and Degradation in Peptic Ulcer Disease

“…Relative deficiency of PGEz synthesis has been suggested, using methods of tissue culture (22,23) and controlled trauma (21). Other studies (29,30), however, have not demonstrated changes in PGE,?…”

“…Studies examining mucosal levels of prostaglandin (19,20) are therefore difficult to interpret, since the majority measured will have been formed during processing. Reservations also apply to studies in which standardized trauma is used (2,21), since this may be difficult to achieve, and other variables are introduced, such as availability of cofactors. Studies of prostaglandin synthesis by cell cultures (22) or mucosal homogenates (24) suffer from the drawback that simultaneous degradation capacity is not measured.…”

Colon cancer chemoprevention: Clinical development of aspirin as a chemopreventive agent

“…In two published studies, there was good reproducibility in PG levels when multiple biopsies were homogenized and assayed repeatedly. But wide variation occurred in prostaglandin levels when assayed separately, suggestive of biological rather than methodological variation [41,42]. Should we measure endogenous prostglandins or in vitro synthesis of prostaglandins?…”

“…Should we measure endogenous prostglandins or in vitro synthesis of prostaglandins? Several different assay methods are available, including measurement of exogenous synthesis of PGs, as in ex vivo culture of colonic biopsies incubated with [ 14 C] arachidonic acid and measurement of radiolabelled products [43,44]; and measurement of endogenous synthesis of PGs, by snap-freezing freshly obtained minimally manipulated tissue, assaying it within an hour of procurement [42,45], and either adding indomethacin to the snap-frozen tissue [41] or homogenizing it at 0°C before incubation at high temperature to stop PG production [45]. Assay recovery may vary with extraction techniques (formic acid/radioimmunoassay method [41] vs. chloroform extraction and gas chromatographymass spectroscopy method [46]).…”