Search PubMed⌕ Search

Biomedical subjects

L E Hanssen

Publications and source records attributed to L E Hanssen.

At least 55 records · Page 3Linked to original sources
PubMed1983

The release of human pancreatic polypeptide, gastrin, gastric inhibitory polypeptide, and somatostatin in celiac disease related to the histological appearance of jejunal mucosa before and 1 year after gluten withdrawal.

Jejunal biopsies and the postprandial response of pancreatic polypeptide (PP), gastrin, gastric inhibitory polypeptide (GIP), and somatostatin have been examined in nine patients with celiac disease before and 1 year after gluten withdrawal. All presented initially with total villous atrophy of the jejunal mucosa. After gluten withdrawal five showed marked mucosal regeneration on light microscopy examination (responders) and four only moderate or no regeneration (nonresponders). Before treatment the celiac patients had enhanced gastrin response and normal PP response compared with normal controls. After gluten withdrawal the integrated gastrin release was reduced to normal in the responders (275 versus 114; p less than 0.05) but remained elevated in the nonresponders (231 versus 204). Postprandial PP release was similar before and after treatment regardless of the degree of mucosal regeneration. In the responders the integrated release of GIP was increased (180 versus 241; p less than 0.05), and the somatostatin release was enhanced (-2.6 versus 8.4; p less than 0.05) after gluten withdrawal. We conclude that the postprandial release of GIP and somatostatin increases and that the release of gastrin decreases when the intestinal mucosa is regenerated in celiacs on a gluten-free diet. The release of PP after food is not influenced by mucosal regeneration.

Adult↗
PubMed1983

Secretin release in coeliac disease. Plasma secretin concentration and bicarbonate output to the duodenum after intraduodenal acid infusion in coeliac patients before and after treatment.

Infusion of 40 ml 0.1 mol/l HCl into the duodenum in eight untreated coeliac patients was followed by an increase of the plasma immunoreactive secretin (IRS) concentration from 1.6 +/- 0.2 pmol/l to a peak level of 2.4 +/- 0.3 pmol/l (p less than 0.05). After treatment with a gluten-free diet, the same patients showed an increase from 1.4 +/- 0.3 pmol/l to a peak level of 5.5 +/- 0.9 pmol/l after intraduodenal acid infusion, which was significantly higher than before treatment (p less than 0.01). In control subjects, intraduodenal acid infusion was followed by an increase from 1.4 +/- 0.2 pmol/l to 6.7 +/- 1.1 pmol/l, which was significantly higher than in untreated coeliac disease (p less than 0.01) but did not differ from what was found in treated coeliac patients. Significant differences in pH, volume, or bicarbonate content of the duodenal aspirates or the basal IRS levels were not found.

Adolescent↗
PubMed1983

Effect of atropine on pancreatic bicarbonate output and plasma concentrations of immunoreactive secretin in response to intraduodenal stimulants.

In conscious dogs with gastric and pancreatic Thomas fistulas we studied the effect of atropine (50 micrograms kg-1 intravenously) on pancreatic bicarbonate output and plasma concentrations of immunoreactive secretin in response to intraduodenal bolus injections of HCl (0.75 mmol), L-tryptophan (1 mmol), and sodium oleate (1 mmol). The 10-min integrated bicarbonate response to HCl was 1.7 times greater than the response to oleate and 2.8 times greater than that to tryptophan. Atropine significantly (p less than 0.05) depressed the 10-min integrated bicarbonate response to HCl, oleate, and tryptophan by 67%, 79%, and 61%, respectively. HCl and oleate, but not tryptophan, significantly increased plasma secretin concentrations over basal levels. Atropine did not significantly alter basal plasma concentrations of secretin or the 10-min integrated plasma secretin response to HCl and oleate. We conclude that 1) intraduodenal tryptophan stimulates pancreatic bicarbonate secretion by an atropine-sensitive mechanism, release of secretin not being involved, and 2) in the presence of atropine the depressed pancreatic bicarbonate response to HCl and oleate is not due to decreased release of endogenous secretin.

Animals↗
PubMed1982

Glucose-induced release of neurotensin after gastric surgery.

The plasma concentration of neurotensin was investigated in 15 patients and 6 healthy persons after oral administration of hypertonic glucose. 8 patients had total gastrectomy, 7 patients had partial gastrectomy of Billroth II type, and 6 nonoperated persons were used as controls. In the gastrectomized patients, the neurotensin concentration increased significantly from 2.0 (n.d.-7.4) pM to 62.4 (12.0-270) pM, in the B II resected patients from 0.9 (0.2-4.2) pM to 4.6 (0.9-59.2) pM. In the unoperated persons the corresponding neurotensin concentrations were 1.7 (0.9-3.4) and 2.2 (0.8-5.3) pM, which were not significantly different. No correlation between neurotensin concentration and dumping symptoms was seen.

Adult↗
PubMed1981

Gastric effects and side effects of synthetic secretin in man.

The gastric effects of synthetic secretin given in a depot preparation as subcutaneous injection or in different doses as intravenous infusion were studied in 10 healthy volunteers. Peptone-stimulated gastric acid secretion and serum gastrin were significantly suppressed with a clear dose-response inhibition of acid output. There was a significant correlation between percentage inhibition of acid secretion and plasma secretin concentrations which were greatly above those seen physiologically. Serum lipase and trypsin increased significantly. Most subjects lost fluid from diuresis and diarrhoea, so that serum sodium and total protein concentrations also increased significantly. These side effects cast doubt on the clinical value of prolonged infusions of pharmacological doses of synthetic secretion in critically ill patients.

Adult↗
PubMed1980

Immunoreactive secretin release following taurocholate perfusions of the cat duodenum.

Perfusion of the cat duodenum with sodium taurocholate (TC), 120 mmol/l, at pH 6.1 increased the plasma immunoreactive (IRS) concentration from 2.2 +/- 0.7 pmol/l to 29 +/- 6.1 pmol/l during the first 20 min. This was accompanied by an increased pancreatic secretion of fluid, while the chymotrypsin output showed a "wash-out' phenomenon. TC increased both the bile-acid-dependent and the bile-acid-independent bile secretion. In comparison, HCl, 150 mmol/l, increased IRS from 0.9 +/- 0.5 pmol/l to 41 +/- 15 pmol/l, producing an increase in the pancreatic fluid secretion. However, only a slight increase in the bile-acid-independent bile secretion was found, and the bile-acid-dependent secretion did not change. The effects of TC on the pancreatic secretion were produced at concentrations occurring in cat hepatic bile.

Animals↗
PubMed1980

The in vitro effect of neurotensin on human jejunal mast cells.

Neurotensin was added to human jejunal mucosal biopsy specimens from six individuals. Fifty-seven per cent degranulation of mast cells was seen at a concentration of neurotensin of 10(-9) M and 43% at 10(-6) M, as compared with 31% with IgE antibody/antigen. There was no change in degranulation with neurotensin when IgE was added to biopsy specimens before neurotensin in a 10(-6) M solution. This effect of neurotensin on human jejunal mast cells supports the evidence for receptors for neurotensin on mast cells shown in rat experiments.

Cytoplasmic Granules↗
PubMed1980

Pure synthetic bile salts release immunoreactive secretin in man.

When 20 ml of 50 mmol/l pure synthetic bile salts (pH 6.5), of approximately the same composition as human bile, were infused into the duodenum of six healthy volunteers over 5 min during constant gastric aspiration, plasma immunoreactive secretin increased from 2.5 +/- 0.4 pmol/l to 3.6 +/- 0.5 pmol/l at 10 min (p < 0.025). Gastric acid secretion was not increased. No effect was seen when the same amount of physiological saline was infused under the same conditions in another group. It is concluded that bile salts in an amount and composition corresponding to that in the human gallbladder is able to release immunoreactive secretin from the human intestine.

Adult↗
PubMed1980

The effect of atropine on secretin release and aspirated bicarbonate secretion after duodenal acidification in man.

The effect of duodenal instillation of hydrochloric acid on peripheral plasma immunoreactive secretin (IRS) concentration--without or with a constant intravenous infusion of atropine--was studied in eight healthy volunteers. Without atropine infusion, IRS increased from 1.2 +/- 0.3 pmol/l to a peak value of 17.1 +/- 4.4 pmol/l. The volume of duodenal aspirates increased from 0.74 +/- 0.12 ml/min to 5.03 +/- 0.46 ml/min, and the bicarbonate output from 7.6 +/- 1.7 mumol/min to 349 +/- 39 mumol/min. With atropine infusion (bolus of 500 micrograms + 750 micrograms/h of atropine sulphate), IRS increased from 1.4 +/- 0.3 pmol/l to 14.8 +/- 3.6 pmol/l. The volume of the duodenal aspirates increased from 0.71 +/- 0.08 ml/min to 2.76 +/- 0.37 ml/min and the bicarbonate output from 4.0 +/- 1.6 mumol/min to 142 +/- 33 mumol/min. The integrated IRS response to acidification was 18% lower during atropine infusion (p < 0.05). Both the aspirated flow rate from the duodenum and the bicarbonate output were markedly reduced by atropine infusion, 45% and 59%, respectively (p < 0.005).

Adult↗
PubMed1980

The effect of glucose on plasma immunoreactive secretin in normal man and after gastrectomy or pancreatectomy.

Oral intake of glucose increased the peripheral plasma immunoreactive secretin (IRS) concentration in patients after total pancreatectomy with duodenectomy (p < 0.05) and in patients after total gastrectomy (p < 0.01). In young healthy volunteers and in patients after partial gastrectomy, no effect on IRS was observed. Intravenous glucose reduced the IRS concentration in pancreatectomized patients (p < 0.05), whereas IRS was only reduced in young healthy volunteers when intravenous glucose was followed by oral glucose after an interval of 10 min (p < 0.025). The abnormal IRS release in pancreatectomized patients and in patients after total gastrectomy might be due to rapid intestinal passage and/or increased splanchnic blood flow induced by hypertonic glucose. A third possibility is that a glucose-induced increase in bile flow might release IRS.

Administration, Oral↗
PubMed1980

Plasma concentration of secretin and gastric secretion following intraduodenal calcium infusion in man.

The aim of the present study was to test whether the previously demonstrated release of immunoreactive plasma secretin following intraduodenal bile infusion could be mediated by the calcium content of the bile. The gastric acid secretion and the serum concentration of gastrin, ionized and total calcium, calcitonin, and parathyroid hormone were also measured. A total amount of 93 mg calcium was infused intraduodenally in eight healthy volunteers during constant gastric aspiration. No effect was seen on the concentration of immunoreactive plasma secretin or serum gastrin levels in peripheral blood. The total serum calcium concentration decreased slightly during the infusion and increased immediately thereafter. Ionized serum calcium increased throughout the experiment, the increase being significant only after the calcium infusion was stopped. No effects were observed on the serum concentrations of calcitonin and parathyroid hormone.

Adult↗
PubMed1980

Exocrine pancreatic secretion and immunoreactive secretin release after repeated intraduodenal infusions of bile in man.

The exocrine pancreatic secretion of water, bicarbonate, amylase, trypsin, chymotrypsin, and lipase and the plasma concentration of immunoreactive secretin (IRS) were studied before and after repeated intraduodenal infusions of cattle bile in man. After endoscopic cannulation of the main pancreatic duct, juice was collected in 5-min samples for 20 min. A solution of 6 g dried cattle bile in 60 ml water was then infused into the duodenum through a separate catheter attached to the outside of the duodenoscope. Juice was collected for another 20 min. After this period a solution of 6 g dried cattle bile in 40 ml water was infused into the duodenum, and juice again collected for 20 min. Blood was frequently drawn from an arm vein for estimation of plasma concentration of secretin by radioimmunoassay. Both bile infusions caused significant rises in flow rate, bicarbonate concentration and output, and IRS (p less than 0.05). Enzyme concentrations decreased significantly after intraduodenal bile infusions (p less than 0.05). Outputs of enzymes rose significantly after the first bile infusion; however, a rise after the second bile infusion was found only for amylase. Further, a significant decrease in amylase and lipase concentration was found after the second bile infusion. The findings indicate that the increase in proteolytic enzyme and lipase secretion was due to a washout phenomenon. The increase in the plasma concentration of secretin after repeated bile infusions, with a corresponding effect on flow rate and bicarbonate secretion, indicates that secretin may be the main factor responsible for the exocrine pancreatic secretion caused by intraduodenal bile infusions.

Adult↗
PubMed1980

The influence of intraduodenal administration of pancreatic juice on the bile-induced pancreatic secretion and immunoreactive secretin release in man.

The exocrine pancreatic secretion of water, bicarbonate, amylase, and protein and the plasma levels of immunoreactive secretin (IRS) were studied after intraduodenal infusions of bile and pancreatic juice. Pancreatic secretion was obtained by endoscopic cannulation of the main pancreatic duct. Bile and pancreatic juice were infused into the duodenum through separate catheters attached to the outside of the duodenoscope. The unstimulated secretion was collected for 20 min. After intraduodenal stimulation of the pancreatic secretion with a nearly neutral solution of dried cattle bile, juice was collected for another 20-min period. Then, pure pancreatic juice was infused into the duodenum. It was shown that pancreatic juice reduced the flow rate and output of bicarbonate, amylase, and protein significantly (p less than 0.05). A significant reduction in plasma concentration of IRS (p less than 0.05) was also found. In the controls, i.e., when no pancreatic juice was instilled into the duodenum, a further increase in flow rate, bicarbonate secretion, and IRS was found. It is concluded that the exocrine pancreatic secretion and IRS release induced by intraduodenal administration of bile may be depressed by reinfusions of pancreatic juice. The corresponding effect on bicarbonate secretion and IRS release found in this study supports the view that secretin may play an important role in the exocrine pancreatic secretion induced by intraduodenal infusion of bile.

Adult↗
PubMed1979

Immunoreactive secretin release in patients after duodenectomy and partial or total pancreatectomy.

Seven patients were investigated 8--22 months after duodenectomy and pancreatectomy for chronic pancreatitis or cancer. Seven other patients, admitted for minor surgery, served as controls. 40 ml 100 mmol/l HCl was infused over 5 min into the jejunum 10 cm beyond the gastrojejunal stoma in the duodenectomized patients and 10 cm beyond the pylorus in the controls. Plasma immunoreactive secretin (IRS) increased from 3.0 +/- 0.8 pmol/l (mean +/- S.E.M.) to 9.8 +/- 0.5 pmol/l (p less than 0.01) in the duodenectomized patients. In the controls the increase was significantly higher than in the patients (p less than 0.01)--from 1.5 +/- 0.3 pmol/l to 19.5 +/- 3.3 pmol/l (p less than 0.01). The study shows that the jejunum is able to release IRS after acid infusion in duodenectomized patients.

Adult↗