review of literature on clinical pancreatology - The Pancreapedia

Studies <strong>of</strong> pancreatic duct secretionThe pancreatic ductal tree conveys enzymatic acinar products to the duodenum and secretesthe fluid and ionic components <strong>of</strong> pancreatic juice. The physiology <strong>of</strong> pancreatic duct cellshas been widely studied, but many questions are still unanswered concerning theirmechanisms <strong>of</strong> ionic transport. Differences in the transport mechanisms operating in theductal epithelium has been described both among different species and in the differentregions <strong>of</strong> the ductal tree. In a <strong>review</strong> it was summarized the methods developed to studypancreatic duct secretion both in vivo and in vitro, the different mechanisms <strong>of</strong> ionic transportthat have been reported to date in the basolateral and luminal membranes <strong>of</strong> pancreaticductal cells and the regulation <strong>of</strong> pancreatic duct secretion by nervous, endocrine andparacrine influences [129].CholecystokininCholecystokinin (CCK)-dependent exocrine pancreatic regulation seems to involve differentpathways in different species. The aims in one study were to explore the enteropancreaticreflex in the CCK-mediated regulation <strong>of</strong> the exocrine pancreas and to evaluate a possibleinvolvement <strong>of</strong> this reflex in the endocrine insulin release. In anesthetized pigs, CCK-33 inincreasing doses (4-130 pmol/kg per 10 min) was infused locally to the gastroduodenalartery, or systemically via the jugular vein. Also, a low CCK-33 dose (13 pmol/kg) wasinjected to the duodenum/antrum area before and after a bilateral truncal vagotomy.Cholecystokinin-33 in the physiological dose range 4 to 32 pmol/kg per 10 min increasedprotein and trypsin outputs after local infusion to the antral-duodenal area, whereas it had noeffect after systemic infusion. Cholecystokinin-33 in the pharmacological dose range 64 to130 pmol/kg per 10 min further increased the secretion after both local and systemicinfusions. Only CCK-33 infusions in the pharmacological dose range were able to elevate theplasma insulin levels. Vagotomy had no effect on CCK-33-mediated stimulation <strong>of</strong> theenzyme release, whereas it had a significant effect on the plasma insulin level [130].Pancreatic function in the elderlyAmong the various studies <strong>of</strong> pancreatic function in the elderly published so far, none havedealt with subjects over 90 years <strong>of</strong> age. The aim <strong>of</strong> one study was to examine pancreaticfunction in healthy individuals over 90 years old. Sixty-eight healthy noninstitutionalizedelderly persons, aged 91-104 years, with a mean age <strong>of</strong> 95 years, and 63 younger controlswere studied. Pancreatic function was studied by determining fecal elastase 1 concentration.In addition to this test, it was also measured serum amylase, pancreatic isoamylase andlipase in 53 <strong>of</strong> the 68 elderly subjects. All but 1 <strong>of</strong> the 68 elderly subjects had normal elastase1 values; the one who did not had a value slightly below normal. No significant differencewith controls was found. Serum pancreatic enzymes were normal in almost all <strong>of</strong> the 53elderly studied; 3 had a mild elevation only <strong>of</strong> amylase and 1 had a persistent elevation <strong>of</strong>amylase, pancreatic isoamylase and lipase. It was concluded that in subjects over 90 years<strong>of</strong> age, exocrine pancreatic function continues to be normal; if an impairment occurs, it ismild and not significant for digestion <strong>of</strong> food. In addition, serum pancreatic enzymes remainwithin normal limits in the vast majority <strong>of</strong> cases [131].Ethanol metabolismTo determine tissue-specific effects <strong>of</strong> alcohol on fatty acid synthesis and distribution asrelated to functional changes in triglyceride transport and membrane formation tissue fatty