Maximal histalog test in control subjects and patients with peptic ulcer.

Each patient to be tested was fasted overnight and in the morning had a tube (16F) passed through the nose. The position of the tube was checked fluoroscopically. The patient remained seated throughout the test. Saliva was expectorated when necessary. Gastric juice was aspirated continuously and mechanically at 30 mm. Hg subatmospheric pressure, with automatic switch-off for 10 out of every 60 seconds. All tests were performed by the same technician. After removal of the residual juice, basal secretion was aspirated for one hour. Histalog (Betazole, 3-beta aminoethylpyrazole dihydrochloride, Lilly) was then injected subcutaneously in a dose of 1-5 mg. per kg. body weight. A dose of this order had been found to evoke maximal secretion in similar patients (Ward et al., 1963) and in a recent report from Brazil (Zaterka and Neves, 1964). The stimulated secretion was aspirated in eight quarter hourly periods. In 12 subjects the whole test was done again within 14 days, in order to assess repeatability. A sample of the aspirated juice was titrated electrometrically to pH 7-0, using 0-2N sodium hydroxide with an autoburette titrator and pH meter (Radiometer, Copenhagen, Denmark).