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Biomedical subjects

C Kolbitsch

Publications and source records attributed to C Kolbitsch.

41 records · Page 3Linked to original sources

Effects of the bradykinin antagonist, icatibant (Hoe 140), on pancreas and liver functions during and after caerulein-induced pancreatitis in rats.

It has been found earlier that the bradykinin antagonist, icatibant (Hoe 140), prevents the pancreatic oedema and the ensuing hypotension and haemoconcentration, and facilitates the removal of activated enzymes form the tissue during caerulein-induced acute pancreatitis. For a potential therapeutic use of the compound in clinical situations it is essential to investigate whether the associated increase in enzyme activities in the blood serum has any adverse effects on the pancreas itself or on other organs. Normal amylase secretion into the biliopancreatic duct stimulated by a low dose of caerulein (0.4 nmol kg-1 h-1, i.v.) was not affect by icatibant (100 nmol kg-1, s.c.) Acute pancreatitis, induced by a high dose of caerulein (4 nmol kg-1 h-1 for 2 h, i.v.), resulted in elevations in the activities of amylase and lipase in the pancreatic tissue and in the blood serum lasting for at least 4 h after the end of the caerulein infusion. While the rise in enzyme activities in the blood serum was augmented in icatibant-treated rats only at the end of the caerulein-infusion, the enzyme accumulation in the pancreas was significantly reduced by icatibant for at least 4 h after the end of the caerulein infusion. The secretion of amylase and lipase into the biliopancreatic duct was significantly increased only during the first 20 min of acute pancreatitis; in rats pre-treated with icatibant, no significant increase could be observed. Twenty-four hours after induction of pancreatitis, a low-dose caerulein stimulation of the exocrine function of the pancreas led to a reduced but sustained secretion of amylase regardless of whether the animals had received icatibant or not. During the first 45 min of pancreatitis, blood glucose concentrations were significantly reduced, but returned to values not different from those obtained in saline-infused controls. This effect was not affected by icatibant. No changes in the response to an i.v. glucose tolerance test were found on the day after induction of acute pancreatitis. The serum activities of glutamic pyruvic transaminase and gamma-glutamyl transpeptidase determined up to 24 h after induction of pancreatitis were not different from saline controls. icatibant had no effect on the activities of these enzymes. It is concluded that during caerulein-induced acute pancreatitis normal exocrine secretion of pancreatic enzymes into the pancreatic duct ceases almost immediately. Pre-treatment with icatibant significantly reduces the accumulation of activated enzymes in the pancreatic tissue for several hours after induction of pancreatitis while a concomitant augmentation in enzyme activities in the blood serum lasts much shorter. There is no indication of adverse effects on the function of the endocrine or exocrine pancreas and that of the liver, either during the acute stages of pancreatitis or during the recovery period.

Acute Disease↗

The impact of peak saturation of the arterial input function on quantitative evaluation of dynamic susceptibility contrast-enhanced MR studies.

PURPOSE: The purpose of this work was to investigate systematic errors in dynamic contrast-enhanced MR perfusion studies due to peak saturation of the arterial input function (AIF) and to introduce a simple correction algorithm. METHOD: Computer simulations were performed to evaluate the influence of AIF peak saturation and to demonstrate the effectiveness of the presented correction algorithm. To compare the computer simulations with real MR data, MR perfusion measurements were performed on volunteers. RESULTS: The computer simulations show that AIF peak saturation leads to a systematic overestimation of cerebral blood volume (CBV) and cerebral blood flow (CBF) values, which was confirmed by comparing the obtained MR data with PET results. With use of an improved calculation algorithm correcting for AIF peak saturation, a significant improvement of the obtained CBV and CBF values could be demonstrated. CONCLUSION: Our results suggest that AIF peak saturation leads to a significant systematic error in the determination of CBV and CBF values and has necessarily to be taken into account for dynamic contrast-enhanced MR perfusion studies.

Adult↗