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Biomedical subjects

L E Hanssen

Publications and source records attributed to L E Hanssen.

10 recordsLinked to original sources
PubMed1992

Raw soybeans stimulate human pancreatic proteinase secretion.

Intraduodenal instillation of raw soybeans stimulated pancreatic proteinase secretion in humans. Raw soybeans almost abolished the activity of chymotrypsin and severely reduced (50%) the tryptic activity. Immunoreactive tryptic and chymotryptic material simultaneously appeared in amounts 2 to 4 times basal concentrations. This increase, demonstrated with rocket immunoelectrophoresis, was begun within the first 10 min of soybean instillation. The enhanced secretion also persisted throughout the succeeding saline instillation, and it is suggested that the presence of Kunitz trypsin inhibitor contributed to this postprandial stimulation. An amidase that hydrolyzes low-molecular-weight substrates (i.e., benzoyl-arginine p-nitroanilide) was found in raw soybeans. Its low activity was not assumed to substantially bias standard trypsin assays. The increased proteinase secretion was, as previously published, not preceded by an elevated plasma cholecystokinin concentration. The raw soybeans also caused a nonparallel secretion of amylase and proteinases. Nervous, perhaps cholinergic, regulation mediates the inhibitor-stimulated proteinase secretion in humans. This stimulation yields both a general increase of proteinases and also a specific inhibitor-resistant trypsin. This is consistent with the physiologic need for proenzyme-activation in the presence of inhibitors and for restoration of the proteolytic capacity of the duodenal juice.

Amylases↗
PubMed1992

The effect of somatostatin analogue SMS 201-995 on serotonin levels in the medium of primary carcinoid cell cultures.

Carcinoid cell cultures were established from primary tumours and liver and mesenteric metastases. The cells continued to produce serotonin for up to 6 months. Cells from different tumours showed different properties. In most wells carcinoid cells grew on a layer of fibroblasts. The tendency to co-culture seemed to be less marked in cells from liver biopsy specimens. The amount of serotonin decreased to 63% 300 min after addition of the somatostatin analogue SMS 201-995 (SMS) to the culture, compared with controls (p < 0.05; n = 10). This decrease was observed up until 12 days, when SMS was added at each change of medium (p < 0.005; n = 8). In the first 10 min, however, SMS induced an increase in serotonin concentration (p < 0.005; n = 11). This effect may be related to other, immediate stimulatory effects of SMS seen in other cell lines originating from neural ridge-derived tissue. We believe it is important to elucidate the properties of individual tumours, as choice of therapy may vary between patients with the same diagnosis. We have described a method to obtain such information within a couple of days, before a definite treatment is selected.

Carcinoid Tumor↗
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↗
PubMed1979

The unstimulated pancreatic secretion obtained by endoscopic cannulation, and the plasma secretin levels in man.

The technique of collecting juice from the main pancreatic duct by siphonage is described. The juice was collected in 5-min fractions under basal conditions for 20 min (32 subjects) and extended to 60 min (6 subjects). Flow rate and bicarbonate concentration were significantly higher during the first collected samples, whereas concentrations of amylase and protein rose during the first 20 min of the study. All variables remained nearly constant after this period. Immunoreactive secretin (IRS) in peripheral plasma was significantly higher immediately after cannulation of the main pancreatic duct, as compared to the pre-endoscopic level. When the catheter was left in the duct and pancreatic juice drained, the IRS stabilized at a level not significantly different from the pre-endoscopic level. Positive correlations were found between flow rate and plasma level of IRS and between flow rate and bicarbonate concentrations. A negative correlation was found between the flow rate and concentrations of amylase and protein. The higher flow rate, plasma level of IRS, and bicarbonate concentration at the beginning of the examination may be due to the presence of acid and/or bile in the duodenal contents shortly after the endoscope enters the duodenum. Later in the procedure the levels have stabilized, which indicates that little or no acid or bile is passing into the duodenum. It is also concluded that secretin may be one factor responsible for the basal pancreatic secretion in man.

Adult↗
PubMed1978

Exocrine pancreatic secretion and immunoreactive secretin (IRS) release after intraduodenal instillation of bile in man.

Six subjects with a normal endoscopic pancreatogram were investigated after an overnight fast by means of a side-viewing duodenoscope. After cannulation of the main pancreatic duct, juice was collected in five-minute samples for 20 minutes. An iso-osmolar solution of 6 g cattle bile was then infused into the duodenum through a separate catheter attached to the outside of the duodenoscope, and pancreatic juice collected in five-minute samples for another 20 minutes. Blood was frequently drawn from an arm vein through an indwelling catheter for estimation of immunoreactive secretin (IRS) by radioimmunassay. The flow rate of pancreatic juice and outputs of bicarbonate, amylase, and protein increased significantly after intraduodenal infusion of bile. A significant rise in plasma IRS was also found after instillation of bile in the duodenum.

Adult↗
PubMed1978

Pancreatic secretion obtained by endoscopic cannulation of the main pancreatic duct and secretin release after duodenal acidification in man.

The main pancreatic duct was cannulated in 12 individuals with a teflon catheter by means of a side-viewing duodenscope. Six individuals received a duodenal infusion of 40 ml 100 mmol/l HCl over 5 min, while the other six served as controls for basal pancreatic secretion. Pancreatic juice was collected in 5-min samples, and blood was frequently drawn for radioimmunoassay of immunoreactive secretin (IRS). In the control group, during 20-min cannulation of the main pancreatic duct, no effect was seen on basal secretion of water, bicarbonate, or alpha-amylase--nor did the IRS levels change. After duodenal acidification there was a significant increase in IRS (p less than 0.02), reaching the highest level at 7 min. The mean flow rate, bicarbonate concentration, and bicarbonate output showed a significant increase as compared to the control group (p less than 0.02), the highest levels being reached in the third 5-min period after the start of the duodenal acidification. The alpha-amylase output was also significantly higher after acidification (p less than 0.02) than in the control group, but the mean alpha-amylase concentration decreased after acidification, reaching its nadir in the third 5-min sample (p less than 0.02). The present results demonstrate a basal and HCl-stimulated pancreatic secretion collected by endoscopic cannulation of the main pancreatic duct in man together with plasma IRS levels.

Adult↗
PubMed1977

Inhibition of secretin release and pancreatic bicarbonate secretion by somatostatin infusion in man.

Five healthy students were investigated on two different days with or without a constant infusion of somatostatin (500 microgram/h) into an arm vein a fluoroscopically placed Lagerlöf tube was used for the collection of gastric and duodenal juice. After 30-min basal period, 40 ml 100 mmol/l HCl was infused into the midpart of the duodenum over 5 min through a thin catheter attached to the tube. Plasma immunoreactive secretin was measured by radioimmunoassay employing 125I-labelled synthetic secretin, antibody against synthetic secretin, and standards prepared from pure natural porcine secretin. Secretin levels without somatostatin infusion were 4.6+/-0.7 pmol/l (mean+/-S.E.M.) basally and rose to a peak of 21.8+/-6.2 pmol/l after duodenal acidification (p less than 0.05) and with somatostatin infusion were 4.4+/-0.4 pmol/l basally and rose to a peak of 6.7+/-1.7 pmol/l (n.s.) after duodenal acidification. Pancreatic bicarbonate output increased from 8.0+/-2.5 mumol/min (mean+/-S.E.M.) to 283+/-44 mumol/min without somatostatin infusion (p less than 0.05) and from 6.7+/-2.1 mumol/min to 70+/-13 mumol/min somatostatin (p less than 0.05). This study shows that somatostatin (500 microgram/h can inhibit the release of secretin and the pancreatic bicarbonate secretion after duodenal acidification in man.

Adult↗
PubMed1977

Radioimmunossay of secretin in human plasma.

A radioimmunoassay is presented which employs 125I-labelled synthetic secretin, antibody against synthetic secretin, and standards prepared from pure natural porcine secretin. Secretin to be measured was extracted into methanol from heparinized plasma containing aprotinin, which together with cysteine hydrochloride was used as stabilizer throughout the assay. With polyethylene glycol separation, a within assay precision of 10% at 17 pmol/1 was found. The between assay precision was 15% at 17 pmol/1 and thelimit of detection 2.5 pmol/1 plasma. Accuracy was 70-85%. The immunoreactive secretin levels in human plasma increased from 4.5+/-0.5 pmol/1 (mean+/-S.E.M.) to 19.5+/-7.5 pmol/1 (mean+/-S.E.M.) after duodenal acidification (n=5). Pancreatic flow rate increased from 0.5+/-0.1 ml/min (mean+/-S.E.M.) to 4.8+/-0.5 ml/min (mean+/-S.E.M.), and bicarbonate output from 9.6+/-1.8 mumol/min (mean+/-S.E.M.) to 268+/-51 mumol/min (mean+/-S.E.M.) after duodenal acidification.

Bicarbonates↗