scholarly journals Metabolism of platelet-activating factor (PAF; 1-O-alkyl-2-acetyl-sn-glycero-3-phosphocholine) and lyso-PAF (1-O-alkyl-2-lyso-sn-glycero-3-phosphocholine) by cultured rat Kupffer cells

1989 ◽  
Vol 261 (1) ◽  
pp. 77-81 ◽  
Author(s):  
W Chao ◽  
A Siafaka-Kapadai ◽  
D J Hanahan ◽  
M S Olson
Keyword(s):  
Bovine Serum Albumin ◽  
Serum Albumin ◽  
Cellular Uptake ◽  
Kupffer Cells ◽  
Bovine Serum ◽  
Platelet Activating Factor ◽  
Metabolic Product ◽  
Supernatant Fraction ◽  
Substantial Influence ◽  
Subsequent Formation

The metabolism of platelet-activating factor (PAF; identified as AGEPC: 1-O-alkyl-2-acetyl-sn-glycero-3-phosphocholine) and lyso-PAF (lyso-GEPC: 1-O-alkyl-2-lyso-sn-glycero-3-phosphocholine) was investigated in cultured rat Kupffer cells. The rat Kupffer cells accumulated [3H]AGEPC and deacetylated this compound to the corresponding [3H]lyso-GEPC, which was the major metabolic product of [3H]AGEPC. [3H]Lyso-GEPC was distributed primarily in the supernatant fraction of incubated cells throughout the experimental interval. Only a very small portion of the [3H]lyso-GEPC was further converted to 1-O-alkyl-2-acyl-sn-glycero-3-phosphocholine (alkylacyl-GPC), indicating that this acylation process was not particularly active in these cells. When [3H]lyso-GEPC was incubated with Kupffer cells, the conversion of lyso-GEPC to AGEPC via the acetyltransferase reaction increased up to 30 min and declined thereafter. Bovine serum albumin (BSA) had a substantial influence on both the cellular uptake and the metabolism of [3H]AGEPC. An increase in the BSA concentration in the incubation media reduced the cellular uptake of [3H]AGEPC and the subsequent formation of lyso-GEPC. The results of this study suggest that the hepatic Kupffer cells play an important role in the metabolism of PAF. Moreover, these results infer that the regulation of the PAF level in certain hepatic pathophysiological situations may be a consequence of the production and subsequent metabolism of this potent lipid autacoid in the Kupffer cells of the liver.

A superfusion bioassay for platelet-activating factor

1989 ◽  
Vol 67 (1) ◽  
pp. 72-74 ◽  
Author(s):  
Giuseppe Cirino ◽  
John L. Wallace
Keyword(s):  
Platelet Aggregation ◽  
Bovine Serum Albumin ◽  
Serum Albumin ◽  
Bovine Serum ◽  
Platelet Activating Factor ◽  
Attractive Alternative ◽  
Organ Bath ◽  
Ascending Colon ◽  
Rat Stomach

A superfusion bioassay for platelet-activating factor is described using various types of tissues. By washing the tissue with 0.1–0.5% bovine serum albumin for 2–3 min after each addition of platelet-activating factor, desensitization did not develop in most tissues studied. Because of the ability to apply a sample directly onto an assay tissue with negligible dilution, this bioassay can detect smaller amounts of platelet-activating factor than those previously reported in which an organ bath was utilized. The ascending colon of the rat and dog appeared to be the most sensitive of the tissues tested, with a limit of detectability in the range of 100–500 fg. Repeated additions of platelet-activating factor could be made for up to 4 h without desensitization. Release of platelet-activating factor from samples of rat stomach was measured using the superfusion bioassay and a platelet aggregation bioassay. There was a significant correlation (r = 0.96; p < 0.01) between the values obtained using the two assay systems. Thus, the sensitivity, the reproducibility, and the inexpensive nature of this bioassay make it an attractive alternative to existing bioassays for platelet-activating factor.Key words: platelet-activating factor – acether, bioassay, colon, superfusion.

N-acetylcysteine delivery with silica nanoparticles into 3T3-L1 adipocytes

2021 ◽  
Author(s):  
Evelyn Frontera ◽  
Martin F Desimone ◽  
Mauricio C De Marzi ◽  
Liliana N Guerra
Keyword(s):  
Bovine Serum Albumin ◽  
Serum Albumin ◽  
Silica Nanoparticles ◽  
Cellular Uptake ◽  
Bovine Serum ◽  
Cytotoxic Effect ◽  
Cellular Accumulation ◽  
Dose Dependent

Background: The addition of 5 mM N-acetylcysteine (NAC) to 3T3-L1 adipocytes culture inhibits the accumulation of triglycerides (Tg) by 50%, but after 48 h uptake was only 16% of total NAC available. Based on these results, the aim of this study is to increase the NAC cellular uptake by encapsulating it in silica nanoparticles (NPs). Materials & methods: Silica NPs, 20 ± 4.5 nm in size, were developed, with an inner cavity loaded with 5 mM NAC. At 48 h after treatment, there was a dose-dependent cytotoxic effect. We attempted to reduce the cytotoxicity of silica NPs by coating them with bovine serum albumin. Results: While we obtained nontoxic bovine serum albumin coated NPs, their effect on Tg cellular accumulation was also reduced.

Pharmacokinetic Analysis of Lectin-dependent Biodistribution of Fucosylated Bovine Serum Albumin: A Possible Carrier for Kupffer Cells

2001 ◽  
Vol 9 (5) ◽  
pp. 341-351 ◽  
Author(s):  
Praneet Opanasopit ◽  
Makiya Nishikawa ◽  
Fumiyoshi Yamashita ◽  
Yoshinobu Takakura ◽  
Mitsuru Hashida
Keyword(s):  
Bovine Serum Albumin ◽  
Serum Albumin ◽  
Kupffer Cells ◽  
Bovine Serum ◽  
Pharmacokinetic Analysis

Improvement of an artificial test substrate technique for evaluation of em immunocytochemical labeling

1987 ◽  
Vol 45 ◽  
pp. 762-763
Author(s):  
G. D. Gagne ◽  
M. F. Miller
Keyword(s):  
Bovine Serum Albumin ◽  
Serum Albumin ◽  
Bovine Serum ◽  
Artificial Substrate ◽  
Chemical Fixation ◽  
As If

We recently described an artificial substrate system which could be used to optimize labeling parameters in EM immunocytochemistry (ICC). The system utilizes blocks of glutaraldehyde polymerized bovine serum albumin (BSA) into which an antigen is incorporated by a soaking procedure. The resulting antigen impregnated blocks can then be fixed and embedded as if they are pieces of tissue and the effects of fixation, embedding and other parameters on the ability of incorporated antigen to be immunocyto-chemically labeled can then be assessed. In developing this system further, we discovered that the BSA substrate can also be dried and then sectioned for immunolabeling with or without prior chemical fixation and without exposing the antigen to embedding reagents. The effects of fixation and embedding protocols can thus be evaluated separately.

Stability of Prostacyclin in Human Plasma and Whole Blood: Studies on the Protective Effect of Albumin

1981 ◽  
Vol 46 (03) ◽  
pp. 645-647 ◽  
Author(s):  
M A Orchard ◽  
C Robinson
Keyword(s):  
Platelet Aggregation ◽  
Bovine Serum Albumin ◽  
Serum Albumin ◽  
Protective Effect ◽  
Whole Blood ◽  
Bovine Serum ◽  
Fatty Acid Content ◽  
Krebs Solution ◽  
Antiaggregatory Activity ◽  
Free Plasma

SummaryThe biological half-life of prostacyclin in Krebs solution, human cell-free plasma or whole blood was measured by bracket assay on ADP-induced platelet aggregation. At 37°C, pH 7.4, plasma and blood reduced the rate of loss of antiaggregatory activity compared with Krebs solution. The protective effect of plasma was greater than that of whole blood. This effect could be partially mimicked by the addition of human or bovine serum albumin to the Krebs solution. The stabilisation afforded by human serum albumin was dependent on the fatty acid content of the albumin, although this was less important for bovine serum albumin.

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