Neurohormonal mechanisms of cigarette smoke-induced duodenal mucosal bicarbonate secretion in the rat.

The effect of cigarette smoke and nicotine on duodenal mucosal bicarbonate secretion (DMBS) was studied in rats. Cigarette smoke but not intravenous nicotine administered acutely to anesthetized rats via a tracheostomy tube stimulated DMBS by 47 +/- 6%. The increase was neurally mediated via atropine-sensitive postganglionic cholinergic neurons.

The effect of cyclic nucleotides on secretin secretion in canine duodenal mucosa in vitro.

We examined the effects of cyclic nucleotides and calcium on secretin release from canine duodenal mucosal explants incubated in organ culture media. Time course studies revealed that at pH 7.4, 5 and 10 mM dibutyryl cyclic adenosine monophosphate (DBcAMP) increased secretin release progressively, reaching a peak at 2 hours.

Basal motor activity of the distal colon: a reappraisal.

The significance of recent motor data on the distal colon in irritable bowel syndrome is obscured by methodological questions such as bowel preparation, variability and reproducibility of motor activity and segmental differences. Thirty subjects were studied after prior bowel cleansing with a water enema on two separate occasions 1 wk apart (10 with one bowel movement per day, 10 with two to three per week, and 10 with three to 12 per day). Two additional studies were performed in 10 of the subjects, one with and one without prior cleansing.

Bile acid and pancreatic trypsin outputs are parallel during intraduodenal infusion of essential amino acids.

There is disagreement as to whether contraction of the gallbladder occurs simultaneously with secretion of pancreatic enzymes during food ingestion. One study that employed exogenous cholecystokinin (CCK) alone showed dissociation of total bile acids (TBA) and trypsin outputs, while another study that employed exogenous CCK plus secretin showed parallel outputs of TBA and trypsin. Since previous studies have suggested that intraduodenal infusion of essential amino acids (EAA) evokes pancreaticobiliary secretion similar to that observed with food ingestion, we infused increasing doses of EAA intraduodenally in 10 subjects with intact gallbladder and in 10 subjects with previous cholecystectomy and measured total bile acids and trypsin outputs serially.