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Biomedical subjects

P Fric

Publications and source records attributed to P Fric.

At least 73 records · Page 4Linked to original sources
PubMed1985

Anionic inhibitors of pancreatic and leukocyte elastase. Alkylamides of 3-carboxypropionyl- and 4-carboxybutyrylalanine peptides.

Low-molecular inhibitors of pancreatic and leukocyte elastase were synthesized of the general formula X-[Ala]n-A [X = Suc and Glt, A = ethylamide, n = 1, 2, 3 and 4; for n = 2 X = H and A = (2-phenylethyl)amide] and of the formula X-[Ala]3-A (X = H, Suc and Glt, A = methyl-, ethyl-, propyl-, isopropyl-, butyl-, isobutyl-, (2-phenylethyl)- and diethylamide; for A = ethylamide, X = maleyl or acetyl). Inhibition constants Ki of these pancreatic and leukocyte elastase inhibitors were determined using the chromogenic substrates Suc-[Ala]4-Nan or Glt-[Ala]4-Nan and Glt-[Ala]3-Val-Nan, respectively. The series of anionic inhibitors containing three alanine residues has the best inhibitory properties. Of the acyl groups, 4-carboxybutyryl appears most advantageous, propylamide is the most suitable of alkylamides for pancreatic elastase, and isobutylamide for leukocyte elastase. Peptides containing a free amino group show an inhibition for pancreatic elastase lower by one order than that of the corresponding acylated derivatives. Glt-[Ala]3-NH-Pr is the best inhibitor of pancreatic elastase with Ki = 0.003mM and Suc-[Ala]3-NH-iBu is the best inhibitor of leukocyte elastase with Ki = 0.7mM.

Animals↗
PubMed1985

Effect of new oligopeptide inhibitors of elastase on acute experimental pancreatitis in the rat.

Acute experimental pancreatitis was induced in male Wistar rats by retrograde injection of 0.4 ml 2% sodium taurocholate into the common choledochopancreatic duct. Prophylactic intraperitoneal injection of 20 mg glutaryl-trialanine-ethylamide, Glt-(Ala)3-NH-Et, 30 min. before induction of pancreatitis reduced the amount of fat necroses and the activity of amylase and lipase in ascites. Repeated intraperitoneal injection of this inhibitor decreased pancreatic hemorrhage. Simultaneous administration of 20 mg Glt-(Ala)3-NH-Et intraperitoneally, and 10 000 KIU of aprotinin intravenously was followed by the most extensive inhibitory effect. Prophylactic and repeated administration of both inhibitors also reduced the area of pancreatic hemorrhage. The same mode of administration of 20 mg undecenoyl-aspartyl-dialanyl-proline-ethylamide, UDE-Asp-(Ala)2-Pro-NH-Et, intraperitoneally and 20 000 KIU of aprotinin intramuscularly, resulted in selective inhibition of fat necroses in all localizations. Glt-(Ala)3-NH-Et and UDE-Asp-(Ala)2-Pro-NH-Et are considered effective inhibitors of various macroscopic and biochemical signs of acute pancreatitis in the rat during short-ferm experiments, if administered prophylactically or early after induction of the disease.

Acute Disease↗
PubMed1983

Cleavage of p-nitroanilides of N-acylated tri- and tetrapeptides by alanine endopeptidase from the brush border membranes of rat enterocytes.

The activity of the alanine endopeptidase from the intestinal brush border was studied using chromogenic substrates of the general formula Sc-Ala2-X-pNA. Sc-Y-Z-Ala-pNA and W-Ala3-pNA respectively. Substrates with C-terminal Leu or Nle are hydrolyzed more readily than Ala-analogues. At least one Ala-residue in one of the positions adjacent to the C-terminus is necessary for the enzyme activity. An Na-substituent has no effect on the activity.

Animals↗
PubMed1983

Comparative study of the estimation of exocrine pancreatic function using p-(N-acetyl-L-tyrosyl)- and p-(N-benzoyl-L-tyrosyl)aminobenzoic acid.

A comparative study using the oral test with chymotrypsin substrates p-(N-acetyl-L-tyrosyl)- and p-(N-benzoyl-L-tyrosyl) aminobenzoic acid (Ac-Tyr-PAB and Bz-Tyr-PAB) was carried out in 43 adults divided into four groups comprising controls (n = 18), chronic pancreatitis (n = 13), after acute pancreatitis (n = 7), and celiac sprue (n = 4), after separate administration of both derivatives and determination of PABA urinary output in 6 and 8 hours. Both derivatives were diagnostically comparable. The specificity of both derivatives in the investigated group in 6 and 8 hours was 100%, and test sensitivity in patients with chronic pancreatitis, was in 6 hours 90.9% for Ac-Tyr-PAB and 72.7% for Bz-Tyr-PAB, and 8 hours 81.8% for both compounds. Differentiation between the controls and the chronic pancreatitis group was better in Ac-Tyr-PAB, as adjudged by the sensitivity and significance of the Student t-test criterion.

4-Aminobenzoic Acid↗