Serum Group I Pepsinogens during Insulin and Pentagastrin Tests in Unoperated and Vagotomized Duodenal Ulcer Patients

Abstract
The level of serum group I pepsinogens (PG I) has been studied during the conventional insulin-pentagastrin test in 29 duodenal ulcer (DU) patients before and 2 months after proximal selective vagotomy (PSV) and in 31 unoperated DU patients. The mean basal serum PG I level was 191.6 .+-. 15.4 .mu.g/l (mean .+-. SEM) before and 143.7 .+-. 24.0 .mu.g/l after PSV. A significant increase in mean serum PG I above the initial value was found in both unoperated DU patients and in patients after PSV 1 h after insulin injection. In 29 PSV patients the mean serum PG I showed a paradoxical decrease during the 2nd h after insulin injection, and the mean postvagotomy serum PG I 2 h after insulin injection was significantly (p < 0.01) lower than the respective preoperative value in the same patients, and the value was close to the basal serum PG I. The low level of serum PG I 2 h after insulin injection in vagotomized patients may reflect the deprivation of the reduced store of PG I in the absence of normal vagal tone. Both the basal serum PG I and serum PG I response during insulin-induced hypoglycaemia showed an overlap between unoperated and vagotomized DU patients. Therefore, serum PG I analyses during the insulin test cannot replace acid secretion tests in the assessment of the completeness of vagotomy.