[Group I pepsinogen (PG I) in the serum and urine after total gastrectomy]

Since the origin of group I pepsinogen (PG I) is no other than gastric mucosa, PG I has been considered to disappear in total gastrectomized patients. We, however, have found proteolytic activity in the urine of one-half of total gastrectomized patients and the activity has proven to be PG I by both gel chromatography and agar gel electrophoresis. Serum and urine PG I levels also have been determined by radioimmunoassay in 40 subjects. PG I was detected in almost all of them and the mean level of serum was 4.17 ng/ml and that of urine was 32.2 ng/ml. The levels had no relation to age and sex but elevated in the patients with recurrent gastric cancer after total gastrectomy. A few possibilities can be considered as to the source of PG I after total gastrectomy, in which heterotopic gastric mucosa or gastric gland metaplasia is most possible. An interesting result in this study was that both serum and urine PG I levels elevated in the recurrent patients. This phenomena suggests that gastric cancer may produce PG I.