scholarly journals Inhibition of Naja Nigricolis Venom Acidic Phospholipase A 2 Catalysed Hydrolysis of Ghost Red Blood Cells by Columbin

2002 ◽  
Vol 17 (1) ◽  
pp. 55-60 ◽  
Author(s):  
A.J. Nok ◽  
E. Balogun ◽  
J.A. Lori ◽  
M.S. Abubakar
Keyword(s):  
Red Blood Cells ◽  
Blood Cells ◽  
Phospholipase A ◽  
Hydrolysis Of ◽  
Phospholipase A 2

scholarly journals THE EFFECT OF VALENCY OF CATIONS AND ANIONS ON NEGATIVELY AND POSITIVELY CHARGED RED BLOOD CELLS

1924 ◽  
Vol 7 (2) ◽  
pp. 225-233 ◽  
Author(s):  
Jean Oliver ◽  
Leonard Barnard
Keyword(s):  
Red Blood Cells ◽  
Blood Cells ◽  
Cell Suspensions ◽  
Ion Concentration ◽  
Degree Of Hydrolysis ◽  
Red Cell ◽  
Hydrolysis Of ◽  
Positively Charged

1. Under comparable conditions, valency effect may be demonstrated with a suspension of red blood cells and the cations and anions of salts. 2. The valency of the cation determines the degree of the effect on negatively charged cells, the valency of the anion, the effect on positively charged cells. 3. Anomalies in valency effects with different salts and red cell suspensions are in part due to variations in H ion concentration, depending on the degree of hydrolysis of the salt.

Snake venom cardiotoxins and bee venom melittin activate phospholipase C activity in primary cultures of skeletal muscle

1991 ◽  
Vol 69 (4) ◽  
pp. 274-281 ◽  
Author(s):  
Jeffrey E. Fletcher ◽  
Ming-Shi Jiang ◽  
Qi-Hua Gong ◽  
Leonard A. Smith
Keyword(s):  
Skeletal Muscle ◽  
Fatty Acids ◽  
Free Fatty Acids ◽  
Red Blood Cells ◽  
Phospholipase C ◽  
Snake Venom ◽  
Blood Cells ◽  
Primary Cultures ◽  
Phospholipase A ◽  
Naja Naja

The effects of cardiotoxin fractions from Naja naja kaouthia and Naja naja atra snake venoms and synthetic melittin peptide were examined on lipolytic activity in red blood cells and primary skeletal muscle cultures. Both native cardiotoxin fractions caused considerable producion of free fatty acids in red blood cells. This production was abolished when the fractions were first treated with p-bromophenacyl bromide to reduce the venom phospholipase A2 activity contamination. In equine and human primary cultures of skeletal muscle, the N. n. kaouthia cardiotoxin (10 μM) and melittin (2 μM) caused a breakdown of phospholipids and production of free fatty acids and diacylglycerol in the absence of lysophospholipid formation. Additionally, melittin at higher concentrations (10 μM) caused triglyceride breakdown. These studies do not support the suggestion that snake venom cardiotoxins and melittin selectively activate endogenous phospholipase A2 activity. Instead, the toxins primarily activate endogenous phospholipase C activity and, in the case of melittin at high concentrations, triglyceride lipase activity.Key words: fatty acids, diacylglycerol, cytotoxins, phospholipase A2, phospholipase C.

scholarly journals Hydrolysis of Phosphatidylserine-exposing Red Blood Cells by Secretory Phospholipase A2Generates Lysophosphatidic Acid and Results in Vascular Dysfunction

2005 ◽  
Vol 281 (2) ◽  
pp. 775-781 ◽  
Author(s):  
Nikole A. Neidlinger ◽  
Sandra K. Larkin ◽  
Amrita Bhagat ◽  
Gregory P. Victorino ◽  
Frans A. Kuypers
Keyword(s):  
Red Blood Cells ◽  
Lysophosphatidic Acid ◽  
Blood Cells ◽  
Vascular Dysfunction ◽  
Secretory Phospholipase ◽  
Hydrolysis Of

scholarly journals Purification of a protease in red blood cells that degrades oxidatively damaged haemoglobin

1991 ◽  
Vol 277 (3) ◽  
pp. 779-786 ◽  
Author(s):  
J M Fagan ◽  
L Waxman
Keyword(s):  
Red Blood Cells ◽  
Molecular Mass ◽  
Blood Cells ◽  
Gel Filtration ◽  
Cell Types ◽  
Insulin Degrading Enzyme ◽  
Multicatalytic Proteinase ◽  
Proteolytic Pathway ◽  
A Subunit ◽  
Hydrolysis Of

Haemoglobin damaged by exposure of red blood cells to oxidants is rapidly degraded by a proteolytic pathway which does not require ATP [Fagan, Waxman & Goldberg (1986) J. Biol. Chem. 261, 5705-5713]. By fractionating erythrocyte lysates, we have purified two proteases which hydrolyse oxidatively damaged haemoglobin (Ox-Hb). One protease hydrolysed small fluorogenic substrates in addition to Ox-Hb. Its molecular mass was approximately 700 kDa and it consisted of several subunits ranging in size from 22 to 30 kDa. This enzyme may be related to the high-molecular-mass multicatalytic proteinase previously isolated from a variety of tissue and cell types. The other Ox-Hb-degrading activity had an apparent molecular mass of 400 kDa on gel filtration, a subunit size of 110 kDa and an isoelectric point between 4.5 and 5.0. This protease also hydrolysed the small polypeptides insulin and glucagon, as well as other large proteins such as lysozyme. Insulin blocked the degradation of Ox-Hb and Ox-Hb blocked the hydrolysis of insulin by the purified protease. Thiol reagents and metal chelators strongly inhibited the hydrolysis of both Ox-Hb and insulin, whereas inhibitors of serine, aspartic and thiol proteases had little effect. These properties suggest that the Ox-Hb-degrading activity purified from rabbit erythrocytes is the cytosolic insulin-degrading enzyme that is believed to play a role in the metabolism of insulin in several tissues. We propose that this enzyme may also function as a key component in a cytoplasmic degradative pathway responsible for removing proteins damaged by oxidants.

Hemoglobin crystals of the red blood cells in the human renal cortex: electron microscopic observations of the renal lithiasis

1978 ◽  
Vol 36 (2) ◽  
pp. 480-481
Author(s):  
Kosuke Ueda ◽  
Hiroto Washida ◽  
Nakazo Watari
Keyword(s):  
Red Blood Cells ◽  
Blood Cells ◽  
Renal Cortex ◽  
Uranyl Acetate ◽  
Osmic Acid ◽  
Renal Lithiasis ◽  
Electron Microscopic ◽  
Hemoglobin C ◽  
First Case ◽  
Ultrathin Sections

IntroductionHemoglobin crystals in the red blood cells were electronmicroscopically reported by Fawcett in the cat myocardium. In the human, Lessin revealed crystal-containing cells in the periphral blood of hemoglobin C disease patients. We found the hemoglobin crystals and its agglutination in the erythrocytes in the renal cortex of the human renal lithiasis, and these patients had no hematological abnormalities or other diseases out of the renal lithiasis. Hemoglobin crystals in the human erythrocytes were confirmed to be the first case in the kidney.Material and MethodsTen cases of the human renal biopsies were performed on the operations of the seven pyelolithotomies and three ureterolithotomies. The each specimens were primarily fixed in cacodylate buffered 3. 0% glutaraldehyde and post fixed in osmic acid, dehydrated in graded concentrations of ethanol, and then embedded in Epon 812. Ultrathin sections, cut on LKB microtome, were doubly stained with uranyl acetate and lead citrate.

Densitometric Identification of Primitive Erythroblasts After Reaction With Diaminobenzidine

1973 ◽  
Vol 31 ◽  
pp. 328-329
Author(s):  
John A. Trotter
Keyword(s):  
Red Blood Cells ◽  
Analytical Method ◽  
Blood Cells ◽  
Guinea Pigs ◽  
Specific Protein ◽  
Visual Examination ◽  
Hemoglobin Synthesis ◽  
Peroxidatic Activity ◽  
Small Density

Hemoglobin is the specific protein of red blood cells. Those cells in which hemoglobin synthesis is initiated are the earliest cells that can presently be considered to be committed to erythropoiesis. In order to identify such early cells electron microscopically, we have made use of the peroxidatic activity of hemoglobin by reacting the marrow of erythropoietically stimulated guinea pigs with diaminobenzidine (DAB). The reaction product appeared as a diffuse and amorphous electron opacity throughout the cytoplasm of reactive cells. The detection of small density increases of such a diffuse nature required an analytical method more sensitive and reliable than the visual examination of micrographs. A procedure was therefore devised for the evaluation of micrographs (negatives) with a densitometer (Weston Photographic Analyzer).

Scanning electron microscopy of erythrophagocytosis by Entamoeba histolytica trophozoites

1992 ◽  
Vol 50 (1) ◽  
pp. 880-881
Author(s):  
Victor Tsutsumi ◽  
Adolfo Martinez-Palomo ◽  
Kyuichi Tanikawa
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Red Blood Cells ◽  
Entamoeba Histolytica ◽  
Causative Agent ◽  
Blood Cells ◽  
Protozoan Parasite ◽  
Complex Phenomenon ◽  
Great Capacity ◽  
Scanning Electron

The protozoan parasite Entamoeba histolytica is the causative agent of amebiasis in man. The trophozoite or motile form is a highly dynamic and pleomorphic cell with a great capacity to destroy tissues. Moreover, the parasite has the singular ability to phagocytize a variety of different live or death cells. Phagocytosis of red blood cells by E. histolytica trophozoites is a complex phenomenon related with amebic pathogenicity and nutrition.

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