摘要:

Human islets from an adult subject with nesidioblastosis were isolated and used to perform in vitro studies. Isolated nesidioblastotic islets showed an increased basal rate of insulin secretion (nesidioblastotic islets, 81.3 ± 6.4 vs. control islets, from cadaveric organ normal donors, 10.2 ± 0.9 μU/islet/90 min) without any further release with increasing glucose concentration. In addition, islets isolated from the pancreas with nesidioblastosis contained more insulin than control islets, 1,547.0 ± 128.7 vs. 935.0 ± 51.7 μU/islet, and the levels of insulin mRNA were also higher than those measured in controls. Interestingly, the serum of the subject with nesidioblastosis contained autoantibodies that stained brightly and selectively a population of islet cells whose distribution coincided with that expected of a cells. In summary, pancreatic islets in nesidioblastosis display β-cell functional abnormalities. Moreover, the finding of antibodies against islet cells is a common feature in the serum of nesidioblastotic subjects; nevertheless, their pathological significance warrants further investigation.

ISSN:0885-3177    

出版商:OVID    

年代:1997

数据来源: OVID

摘要:

Exocrine pancreas from different species behaves differently in response to the presence of intact or digested nutrients in the duodenum. A failure of cholecystokinin (CCK) release after a meal has been shown among patients with exocrine pancreatic insufficiency. This abnormality could be restored by the administration of pancreatic extracts, suggesting that digested rather than intact nutrients are responsible for the release of CCK and subsequently gallbladder contraction in humans. The aim of this study was to determine the specific role of different lipidic stimuli in humans. Seven male patients (mean age, 52 years) with pancreatic insufficiency secondary to chronic pancreatitis were selected. Pancreatic insufficiency was considered severe in five of them (lipase output, < 1,000 IU/min) and moderate in another two (lipase output, > 1,000 and <2,300 IU/min). Plasma CCK (by bioassay), gallbladder contraction (by ultrasound), and enzyme output (chymotrypsin) in response to duodenal administration of either oleic acid as free fatty acids or 20% Intralipid as triglycerides were measured in each patient with at least a 48-h interval between each test. In all these patients with pancreatic insufficiency, duodenal perfusion of free fatty acids generated a more pronounced (91 ± 11 vs. 49 ± 21 pM) and faster (15 vs. 30 min) (p< 0.05) CCK release than triglycerides. Furthermore, gallbladder contraction was more efficient when free fatty acids instead of triglycerides were administered in the duodenum (86 ± 5 vs. 69 ± 4%) at 10 min (p< 0.05) and (73 ± 8 vs. 51 ± 5%) at 15 min (p< 0.03). Among patients with measurable residual pancreatic function, enzyme outputs were shown to be higher during free fatty acid than triglyceride perfusion. In humans, free fatty acids rather than triglycerides, when present in the duodenum, stimulate CCK release and gallbladder contraction. In patients with moderate pancreatic insufficiency this phenomenon may increase residual enzymatic secretion. These results allow us to encourage the development of enzymatic preparations as acid-resistant lipases that cause a fast release of free fatty acids in the duodenum.

ISSN:0885-3177    

出版商:OVID    

年代:1997

数据来源: OVID

摘要:

Although there is considerable evidence indicating the existence of important cholinergic neural regulation of pancreatic function, very little is known about the action of acetylcholine on pancreatic ganglion neurons. The present study was undertaken to determine the effect of pressure microejection of acetylcholine and muscarine on ganglion cell excitability of the cat pancreas. Recordings were made in vitro from ganglion neurons located in the head region of the pancreas. Acetylcholine evoked a fast- and a slow-developing membrane depolarization in the majority of neurons tested. A decrease in membrane input resistance accompanied the fast depolarizing response, whereas an increase in input resistance accompanied the slow depolarizing response. The fast response was mimicked by 1, 1-dimethyl-4-phenylpiperazinium iodide and nicotine and antagonized by hexamethonium. The slow depolarizing response was mimicked by muscarine and antagonized by atropine and pirenzepine. The dependence of the slow depolarization on extracellular K+and the distinct voltage dependence of the slow depolarization suggest that activation of muscarinic receptors was due to inactivation ofIM. The slow excitatory postsynaptic potential and associated increase in excitability evoked by repetitive nerve stimulation was partially cholinergic dependent in the majority of neurons tested. It was concluded that cholinergic transmission in cat pancreatic ganglia involves nicotinic and M, receptors that mediate fast and slow synaptic transmission, respectively, and that activation of M1receptors modifies the output firing frequency.

ISSN:0885-3177    

出版商:OVID    

年代:1997

数据来源: OVID

摘要:

Epidermal growth factor (EGF) is a mitogenic stimulus in many tissues and occurs in large amounts in the pancreas and salivary glands. Whether EGF is mitogenic in the pancreas is controversial, and the EGF effect has not been studied in the salivary glands. Therefore, the aim of the present study was to investigate the possible effects on the pancreas and parotid and submandibular glands at different time intervals after exogenous EGF administration. Human recombinant EGF was infused subcutaneously by osmotic minipumps in three groups of mice (for 1, 3, and 7 days, respectively) at a dosage of 10 μg/kg/h (1.6 μmol/kg/h). Tritiated thymidine was infused intraperitoneally by osmotic minipumps for the same time periods, but only for the last 3 days in the 7-day group. After 1 day the pancreas increased in weight and the increase persisted throughout the study. No effect was seen on the parotid or submandibular gland wet weight. A slight transient increase in pancreas protein content was observed, whereas amylase content was unaffected. The labeling index of serous and ductal cells in the parotid gland increased from the third day. After 7 days, all cell types studied in the pancreas and parotid and submandibular glands were in a hyperproliferative state. The results show that EGF evoked a strong proliferative response on all cell types studied in the pancreas and parotid and submandibular glands.

ISSN:0885-3177    

出版商:OVID    

年代:1997

数据来源: OVID

ISSN:0885-3177    

出版商:OVID    

年代:1997

数据来源: OVID

ISSN:0885-3177    

出版商:OVID    

年代:1997

数据来源: OVID

ISSN:0885-3177    

出版商:OVID    

年代:1997

数据来源: OVID

ISSN:0885-3177    

出版商:OVID    

年代:1997

数据来源: OVID

ISSN:0885-3177    

出版商:OVID    

年代:1997

数据来源: OVID