Ten subjects received secretin and cholecystokinin or, in duplicate tests, the two hormones together with either diazepam or diazepam plus hyoscine butylbromide in order to determine whether these drugs, which are often used during retrograde endoscopic cannulation of the pancreatic duct, affect pancreatic and biliary secretion in response to the hormones. Diazepam with hyoscine butylbromide reduced the secretion of trypsin into the duodenum and delayed the appearance of both trypsin and bilirubin in duodenal aspirate. These effects must be taken into account when interpreting pancreatic and biliary responses measured during direct cannulation of the pancreatic duct.

The effect of cimetidine, a new histamine H2-receptor antagonist, on gastric acid secretion stimulated by a homogenised meal was studied in six normal volunteers using an in vivo intragastric titration technique. The subjects were studied twice, no more than 48 h apart, receiving either cimetidine 200 mg or placebo in random order. Cimetidine administered either 32 men before (three subjects) or with the meal (three subjects) significantly inhibited gastric acid secretion in all the subjects throughout the period of study; 96 min after food, total acid secretion decreased by 67 and 57% respectively. When the drug was taken with the meal absorption was slower (mean peak blood level 2-34 mumol/l, 80-128 min after dosing) than when administered on an empty stomach (mean peak blood level 5-08 mumol/l, 48-64 min after dosing). Blood cimetidine concentration correlated significantly (P less than 0-01) with percentage inhibition of acid output and the calculated concentration resulting in 50% inhibition of gastric acid secretion (IC50) was 1-6 mumol/l. Secretion of gastrin in response to food was unaffected by cimetidine. The results suggest that 200 mg cimetidine effectively inhibits food-stimulated acid secretion and that the bioavailability of the drug may be affected by the timing of dosage in relation to meals. No unwanted effect were observed.

The effect of H2-receptor blockade on intragastric acidity was studied in nine normal males. The pH of their gastric contents was measured at hourly daytime and two hourly nighttime intervals for 48 hours. The subjects ate identical meals, drank identical volumes of fluid, and smoked the same number of cigarettes during the two study days. Their physical activity was unrestricted in a ward environment. Blood cimetidine and plasma gastrin were measured in serial blood samples. The nine subjects were treated in random sequence with cimetidine 0-8-1-0 g on one day and placebo capsules on the other. The drug was given in four divided doses: four subjects received it before, and five after, the three main meals. All took the fourth dose at bedtime. Replicate studies in an additional subject given placebo on both study days showed good reproducibility (r=0-80, P less than 0-01). Cimetidine therapy decreased intragastric acidity in all nine subjects. The decrease was similar in the two groups taking the drug before or after meals, mean 24 h intragastric hydrogen ion activity being lowered by 70 and 72% respectively. Nocturnal anacidity was recorded in only two of 45 samples. Administration of cimetidine before meals produced earlier and higher drug blood levels than post-prandial medication, but when it was taken after food the blood levels were highest at the time when the buffer capacity of the food was waning. Blood concentrations of cimetidine exceeded the secretory IC50 level for most of the time between doses. The results show that cimetidine 0-8-1-0 g/day in four divided doses produces a striking and consistent decrease of intragastric acidity. Although variation in the timing of the dose in relation to meals did not affect the decrease of acidity, the absorption data suggest that patients should take the drug after meals.

The effect of glucagon on human colonic myoelectrical activity is described. By means of intraluminal, serosal, and surface electrodes, recordings from all areas of the large bowel have been obtained. Glucagon inhibited both electrical and pressure rhythms in all subjects tested. Evidence is produced to suggest a direct action on colonic smooth muscle. A controlled trial using glucagon during routine barium enema examinations suggests that it may prove to be useful for hypotonic examinations of the colon where painful spasm is present.

Among 120 consecutive patients with chronic active liver disease (CALD) randomized to different treatments, those receiving maintenance doses of prednisone 20 mg daily (Pred), prednisone in doses given on alternate days and titrated to secure resolution of clinical and biochemical abnormalities (Pred-Titrad), or a combination of prednisone 10 mg and azathioprine 50 mg daily (Comb) survived and underwent resolution of clinical and biochemical features of disease more often than a control group receiving placebo or azathioprine 100 mg daily. Histological remission occurred significantly more often with Pred and Comb than with other regimens. Major side-effects of therapy were commoner with Pred than with Comb or Pred-Titrad, which did not differ. We conclude that Comb is the initial treatment of choice for CALD, since clinical, biochemical, and histological resolution of disease activity occurs as often as with Pred, whereas early side-effects are significantly less frequent.

The quantification of gastric, pancreatic, biliary, and small bowel functions in man often requires the use of intestinal tubes. In this study, the presence of a transpyloric tube did not alter gastric emptying, acid secretion, or serum gastrin levels in response to an ordinary solid meal.