Biomaterial Database

Clearance and metabolism of circulating pancreatic proelastase in the rat. 1980

C Largman, and S B Ray, and J W Brodrick, and M C Geokas

A rat model has been employed to study the mechanism of clearance of pancreatic proelastase from the circulation. The clearance of 125I-labeled proelastase was shown to be biphasic, with a half-life for clearance of free 25,000-dalton proelastase of approximately 7-10 min. A slow component of clearance possibly due to proelastase associated with plasma protease inhibitors was also observed. At 10 min after injection of 125I-labeled proelastase into the circulation, the major fraction of the 125I was found to be localized in the kidney. However, appearance of 125I in urine is slow, with 16 h being required for excretion of 50% of the injected 125I as acid-soluble material. Subcellular localization experiments on homogenates of kidneys removed at 10 min postinjection revealed that the majority of the 125I-labeled material was associated with the mitochondrial and lysosomal fraction. Sucrose-gradient centrifugation studies of this fraction demonstrated that the labeled material passes from the membrane fraction to the lysosomal fraction with time. These data demonstrate that the rat kidney constitutes the major site for both circulatory clearance and catabolism of circulating pancreatic proelastase.

UI	MeSH Term	Description	Entries
D007668	Kidney	Body organ that filters blood for the secretion of URINE and that regulates ion concentrations.	Kidneys
D008297	Male		Males
D008657	Metabolic Clearance Rate	Volume of biological fluid completely cleared of drug metabolites as measured in unit time. Elimination occurs as a result of metabolic processes in the kidney, liver, saliva, sweat, intestine, heart, brain, or other site.	Total Body Clearance Rate,Clearance Rate, Metabolic,Clearance Rates, Metabolic,Metabolic Clearance Rates,Rate, Metabolic Clearance,Rates, Metabolic Clearance
D008970	Molecular Weight	The sum of the weight of all the atoms in a molecule.	Molecular Weights,Weight, Molecular,Weights, Molecular
D010179	Pancreas	A nodular organ in the ABDOMEN that contains a mixture of ENDOCRINE GLANDS and EXOCRINE GLANDS. The small endocrine portion consists of the ISLETS OF LANGERHANS secreting a number of hormones into the blood stream. The large exocrine portion (EXOCRINE PANCREAS) is a compound acinar gland that secretes several digestive enzymes into the pancreatic ductal system that empties into the DUODENUM.
D010196	Pancreatic Elastase	A protease of broad specificity, obtained from dried pancreas. Molecular weight is approximately 25,000. The enzyme breaks down elastin, the specific protein of elastic fibers, and digests other proteins such as fibrin, hemoglobin, and albumin. EC 3.4.21.36.	Elastase,Pancreatopeptidase,Elastase I,Pancreatic Elastase I,Elastase I, Pancreatic,Elastase, Pancreatic
D011485	Protein Binding	The process in which substances, either endogenous or exogenous, bind to proteins, peptides, enzymes, protein precursors, or allied compounds. Specific protein-binding measures are often used as assays in diagnostic assessments.	Plasma Protein Binding Capacity,Binding, Protein
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D014018	Tissue Distribution	Accumulation of a drug or chemical substance in various organs (including those not relevant to its pharmacologic or therapeutic action). This distribution depends on the blood flow or perfusion rate of the organ, the ability of the drug to penetrate organ membranes, tissue specificity, protein binding. The distribution is usually expressed as tissue to plasma ratios.	Distribution, Tissue,Distributions, Tissue,Tissue Distributions
D051381	Rats	The common name for the genus Rattus.	Rattus,Rats, Laboratory,Rats, Norway,Rattus norvegicus,Laboratory Rat,Laboratory Rats,Norway Rat,Norway Rats,Rat,Rat, Laboratory,Rat, Norway,norvegicus, Rattus