Evidence of glomerular epithelial cell endocytosis in vitro. 1981

M M Schwartz, and Z Sharon, and A K Bidani, and B U Pauli, and E J Lewis

The disappearance rate of protamine-heparin aggregates (PHA) from the lamina rara externa of the glomerular basement membrane was determined in vitro to better characterize the clearance mechanism. Sprague-Dawley rats were injected intravenously with protamine, followed by a neutralizing dose of heparin, and the glomeruli were isolated and incubated in Dulbecco's tissue culture medium. After obtaining a baseline sample, aliquots were taken every 10 minutes for an hour. The samples were processed for electron microscopy, and the numerical density of PHA in the lamina rara externa was determined using a computerized morphometric technique. Disappearance curves for PHA were constructed by expressing the numerical density at each point as a percentage of the baseline value and plotting the logarithm against time. At 37 degree C., the disappearance of PHA was rapid (t 1/2 = 24 minutes), followed first order kinetics (R2 = 0.9948), and was almost complete by 1 hour. The epithelial cells took up PHA by an endocytic process. Significant inhibition of PHA disappearance was achieved when the glomeruli were incubated at 4 degree C. and with 10(-3) M NaF. These data indicate that PHA disappearance is an energy-dependent cell function, and it was concluded that glomerular epithelial cell endocytosis is the principal mechanism of PHA clearance.

UI MeSH Term Description Entries
D007035 Hypothermia Lower than normal body temperature, especially in warm-blooded animals. Hypothermia, Accidental,Accidental Hypothermia,Accidental Hypothermias,Hypothermias,Hypothermias, Accidental
D007678 Kidney Glomerulus A cluster of convoluted capillaries beginning at each nephric tubule in the kidney and held together by connective tissue. Glomerulus, Kidney
D011479 Protamines A group of simple proteins that yield basic amino acids on hydrolysis and that occur combined with nucleic acid in the sperm of fish. Protamines contain very few kinds of amino acids. Protamine sulfate combines with heparin to form a stable inactive complex; it is used to neutralize the anticoagulant action of heparin in the treatment of heparin overdose. (From Merck Index, 11th ed; Martindale, The Extra Pharmacopoeia, 30th ed, p692) Protamine,Protamine Sulfate,Protamine Chloride,Chloride, Protamine,Sulfate, Protamine
D004705 Endocytosis Cellular uptake of extracellular materials within membrane-limited vacuoles or microvesicles. ENDOSOMES play a central role in endocytosis. Endocytoses
D004847 Epithelial Cells Cells that line the inner and outer surfaces of the body by forming cellular layers (EPITHELIUM) or masses. Epithelial cells lining the SKIN; the MOUTH; the NOSE; and the ANAL CANAL derive from ectoderm; those lining the RESPIRATORY SYSTEM and the DIGESTIVE SYSTEM derive from endoderm; others (CARDIOVASCULAR SYSTEM and LYMPHATIC SYSTEM) derive from mesoderm. Epithelial cells can be classified mainly by cell shape and function into squamous, glandular and transitional epithelial cells. Adenomatous Epithelial Cells,Columnar Glandular Epithelial Cells,Cuboidal Glandular Epithelial Cells,Glandular Epithelial Cells,Squamous Cells,Squamous Epithelial Cells,Transitional Epithelial Cells,Adenomatous Epithelial Cell,Cell, Adenomatous Epithelial,Cell, Epithelial,Cell, Glandular Epithelial,Cell, Squamous,Cell, Squamous Epithelial,Cell, Transitional Epithelial,Cells, Adenomatous Epithelial,Cells, Epithelial,Cells, Glandular Epithelial,Cells, Squamous,Cells, Squamous Epithelial,Cells, Transitional Epithelial,Epithelial Cell,Epithelial Cell, Adenomatous,Epithelial Cell, Glandular,Epithelial Cell, Squamous,Epithelial Cell, Transitional,Epithelial Cells, Adenomatous,Epithelial Cells, Glandular,Epithelial Cells, Squamous,Epithelial Cells, Transitional,Glandular Epithelial Cell,Squamous Cell,Squamous Epithelial Cell,Transitional Epithelial Cell
D004848 Epithelium The layers of EPITHELIAL CELLS which cover the inner and outer surfaces of the cutaneous, mucus, and serous tissues and glands of the body. Mesothelium,Epithelial Tissue,Mesothelial Tissue,Epithelial Tissues,Mesothelial Tissues,Tissue, Epithelial,Tissue, Mesothelial,Tissues, Epithelial,Tissues, Mesothelial
D006493 Heparin A highly acidic mucopolysaccharide formed of equal parts of sulfated D-glucosamine and D-glucuronic acid with sulfaminic bridges. The molecular weight ranges from six to twenty thousand. Heparin occurs in and is obtained from liver, lung, mast cells, etc., of vertebrates. Its function is unknown, but it is used to prevent blood clotting in vivo and vitro, in the form of many different salts. Heparinic Acid,alpha-Heparin,Heparin Sodium,Liquaemin,Sodium Heparin,Unfractionated Heparin,Heparin, Sodium,Heparin, Unfractionated,alpha Heparin
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
D012969 Sodium Fluoride A source of inorganic fluoride which is used topically to prevent dental caries. Fluoristat,Ossin,Zymafluor,Fluoride, Sodium,Fluorides, Sodium,Fluoristats,Ossins,Sodium Fluorides,Zymafluors
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

Related Publications

M M Schwartz, and Z Sharon, and A K Bidani, and B U Pauli, and E J Lewis
January 1992, Nephron,
M M Schwartz, and Z Sharon, and A K Bidani, and B U Pauli, and E J Lewis
January 1991, Nephrology, dialysis, transplantation : official publication of the European Dialysis and Transplant Association - European Renal Association,
M M Schwartz, and Z Sharon, and A K Bidani, and B U Pauli, and E J Lewis
January 1990, Nephrology, dialysis, transplantation : official publication of the European Dialysis and Transplant Association - European Renal Association,
M M Schwartz, and Z Sharon, and A K Bidani, and B U Pauli, and E J Lewis
April 1990, Kidney international,
M M Schwartz, and Z Sharon, and A K Bidani, and B U Pauli, and E J Lewis
January 1981, Nephron,
M M Schwartz, and Z Sharon, and A K Bidani, and B U Pauli, and E J Lewis
January 1980, Scanning electron microscopy,
M M Schwartz, and Z Sharon, and A K Bidani, and B U Pauli, and E J Lewis
April 1990, Archives of biochemistry and biophysics,
M M Schwartz, and Z Sharon, and A K Bidani, and B U Pauli, and E J Lewis
December 1990, International journal of experimental pathology,
M M Schwartz, and Z Sharon, and A K Bidani, and B U Pauli, and E J Lewis
October 1989, The Journal of pathology,
M M Schwartz, and Z Sharon, and A K Bidani, and B U Pauli, and E J Lewis
January 2005, Contributions to nephrology,
Copied contents to your clipboard!