Inhibitory effect of new anticholinergics on the basal and secretin-stimulated pancreatic secretion in patients with and without pancreatic disease: therapeutic and theoretic implications

An overview of the diagnosis and management of nutrition in chronic pancreatitis

Chronic pancreatitis is characterized by long-standing inflammation of the pancreas, which results in fibrosis and the gradual loss of pancreatic function. The loss of islets and acinar cells results in diabetes and exocrine insufficiency, respectively. Exocrine insufficiency can result in maldigestion of fat, protein, and carbohydrate as well as vitamins and minerals. Patients may present with variable severity of disease, from mild to severe. The diagnosis of chronic pancreatitis can be challenging, especially in patients with early or mild disease who have few to no morphologic abnormalities on standard abdominal imaging studies. A number of imaging modalities and tests have evolved to aid in the diagnosis of chronic pancreatitis based on changes in structure or function. Clinicians typically focus on treating pain in chronic pancreatitis as opposed to exocrine insufficiency, despite the fact that maldigestion and malabsorption can result in nutrition deficiencies. The aims of this review are to describe the various modalities used to diagnose chronic pancreatitis, to illustrate the nutrition deficiencies associated with exocrine insufficiency, and to provide an overview of nutrition assessment and treatment in these patients.

The effect of moderate sedation on exocrine pancreas function in normal healthy subjects: a prospective, randomized, cross-over trial using the synthetic porcine secretin stimulated Endoscopic Pancreatic Function Test (ePFT)

BACKGROUND

We have developed a purely endoscopic collection method for the assessment of pancreatic secretory function (ePFT). The pancreatic secretory effects of sedation medications utilized during endoscopic procedures are not completely known.

AIMS

To study the effect of moderate sedation on the exocrine pancreas gland in a prospective, randomized trial.

METHODS

Healthy volunteers were randomized by computers to one of two treatments (A-no sedation, B-sedation) in period 1 and crossed-over to the other treatment in period 2 with a minimal washout interval of 7 days. Sedation dosage was standardized for each patient based on age, gender and weight from a previously published dosing nomogram. Synthetic porcine secretin (ChiRhoClin, Inc., Burtonsville, Maryland) was used as the pancreatic stimulant. Duodenal fluid samples were aspirated via the endoscope every 5 min for 1 h and sent on ice to our hospital laboratory for the measurement of pancreatic secretory electrolyte concentrations by autoanalyzer.

RESULTS

A total of 17 healthy volunteers were enrolled. Sixteen subjects (8 males and 8 females) completed the randomized prospective trial. Median intravenous meperidine and midazolam sedation dose was 62.5 mg and 2.5 mg, respectively. Maximum pancreatic juice flow occurred during the early phase of secretion and maximum bicarbonate concentration occurred during the late phase of secretion. Analysis of the electrolyte composition of the endoscopically collected duodenal drainage fluid revealed a constant cation concentration for both sodium and potassium over the 1 h collection period. The anions, chloride and bicarbonate, exhibited a reciprocal relationship identical to that seen in traditional gastroduodenal tube collection studies. There was no statistical difference observed between the sedation and no sedation groups. The estimated total bicarbonate output (area under curve, AUC) for the sedated and non-sedated groups were 5,017 meq + 724 (range 3,663-6,173) and 5,364 meq +/- 583 (range 4,323-6563) respectively (p= 0.0656). The mean peak bicarbonate concentrations for sedated (n = 8) versus non-sedated (n = 8) groups were 103 +/- 11 meq/L (range 78-125) and 106 +/- 11 meq/L (range 87-138), respectively (p= 0.1346). There was excellent correlation of peak bicarbonate concentrations when sedation and no sedation groups were compared (r= 0.744, p < 0.05; Spearman rank correlation). There were no episodes of pancreatitis.

CONCLUSIONS

(a) Moderate sedation used for upper endoscopy does not effect the clinical diagnostic parameters (peak bicarbonate concentration or total bicarbonate output) utilized to diagnose pancreatic insufficiency. (b) Analysis of duodenal drainage fluid collected endoscopically after synthetic secretin stimulation produces an identical pancreatic secretory curve described with traditional gastroduodenal tube collection methods.

Effect of diazepam and hyoscine butylbromide on response to secretin and cholecystokinin-pancreozymin in man

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.

Mechanism of release of endogenous cholecystokinin by jejunal amino acid perfusion in man

Ertan et al have shown that the perfusion of the proximal jejunum with a mixture of amino acids (MAA) in physiological concentration releases endogenous cholecystokinin (CCK) in man. In the present experiment, we investigate the mechanism by which jejunal MAA perfusion mediates an increase in exocrine pancreatic and biliary secretions. The effects of a bolus of topical anesthetic (oxethazaine, 0.5 mg/kg of 0.4% solution) or the simultaneous jejunal perfusion of a topical anticholinergic agent (atropine, 1 mg/liter) were studied in the same five normal patients on different days. Suppression of the response to jejunal MAA perfusion but not to intravenous infusion of CCK or jejunal saline perfusion, was noted in these normal subjects following jejunal application of oxethazaine and atropine. These results suggest a local involvement of the cholinergic mechanism for the endogenous release of CCK, while exogenous CCK acts directly on the pancreatic cells.

Bile production in fasted and fed primates

Previous experiments have suggested differences in the bile salt independent flow rate between monkeys and dogs, and in the ability of bile salt secretion to influence bile flow. The present study was performed to determine whether the availability of food could have influenced these results. Bile flow and bile salt secretion rates were studied in fasted and fed primates. In the fasting experiments, sodium cholate, sodium taurocholate, and monkey bile were infused into the duodenum; only sodium cholate was infused in the feeding experiments. The results showed that bile flow was linearly related to the bile salt secretion rate in both fasting and feeding animals. Bile salt independent flow is extremely variable during fasting and is increased and stabilized by feeding. These studies indicate that the differences found in previous experiments are probably attributable to variations in experimental design.

Inhibition of pancreatic secretion in man by cigarette smoking

Cigarette smoking has been linked to an elevated incidence of duodenal ulcer disease in smokers, although the mechanism is unclear. In 23 young normal subjects single or double secretin tests were performed during non-smoking and smoking periods. Cigarette smoking inhibited the secretion of pancreatic juice and bicarbonate in light smokers (< one pack/day for < three years). Heavy smokers (> one pack/day for > three years) exhibited depressed pancreatic secretory rates during non-smoking periods. Inhibition of pancreatic alkaline secretion by cigarette smoking could be the link between the habit and duodenal ulcer disease.