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.

Albumin reduces basement membrane hydraulic conductance in part due to arginyl side groups

1995 ◽  
Vol 269 (5) ◽  
pp. H1514-H1521 ◽  
Author(s):  
M. A. Katz ◽  
M. L. La Marche
Keyword(s):  
Extracellular Matrix ◽  
Bovine Serum Albumin ◽  
Basement Membrane ◽  
Serum Albumin ◽  
Protective Effect ◽  
Binding Sites ◽  
Bovine Serum ◽  
Hydraulic Conductance ◽  
Experimental Control ◽  
Low Concentrations

Albumin reduces capillary hydraulic conductance (Lp) even at low concentrations. To determine if part of this barrier protective effect might be extracellular, we studied the effects of bovine serum albumin (BSA) on Lp of self-assembled basement membrane (Matrigel). Lp with tris(hydroxymethyl)aminomethane (Tris) buffer superfusate was stable at 1.77 +/- 0.22 x 10(-5) (SE) cm.s-1.cmH2O-1 over several hours. At 0.1 g/dl BSA, experimental/control (Tris) Lp fell to 83.1 +/- 6.0% (2P < 0.025), with decreases to 72.4 +/- 3.7% at 1 g/dl (2P < 0.005), 45.3 +/- 5.1% at 2.5 g/dl (2P < 0.001), and 45.0 +/- 4.8% at 4.0 g/dl (2P < 0.001). In separate experiments, BSA arginine groups were neutralized by 1,2-cyclohexanedione (CHD), and experimental/control Lp values were measured. At 2.5 g/dl, CHD-BSA depressed Lp to 54.4 +/- 4.8%, while unmodified BSA reduced Lp to 40.8 +/- 3.5% of Tris control (2P = 0.05). Finally, soluble arginine at three- and sixfold the arginine in BSA was added to BSA superfusate. For threefold, Lp rose to 120 +/- 8% of BSA level and for sixfold to 129 +/- 9% (2P < 0.05). We conclude that some part of the albumin protective effect is very likely due to consequences on extracellular matrix and that at least 18-22% of this effect is related to arginine groups on albumin when computed from Lp, and up to 34% when viscosity is taken into account. Membrane-saturable arginine-binding sites can be unbound with arginine, thus nullifying part of the barrier protective effect of BSA.

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.

THE USE OF DUBOS OLEIC ACID ALBUMIN MEDIUM ENRICHED WITH BLOOD FOR THE VIABLE COUNTING OF BCG

1956 ◽  
Vol 2 (3) ◽  
pp. 393-401 ◽  
Author(s):  
Doraine C. W. Thow
Keyword(s):  
Oleic Acid ◽  
Bovine Serum Albumin ◽  
Serum Albumin ◽  
Whole Blood ◽  
Bovine Serum ◽  
Freeze Drying ◽  
Maximum Size ◽  
Colony Count

Several different media were compared by means of surface viable counts of suspensions, in 0.1% solution of bovine serum albumin, of freshly grown BCG, and of BCG resuspended after freeze-drying. The growth of BCG on oleic acid albumin medium enriched with 5% whole blood was best in three respects: from a given inoculum, the colony count was highest; the colonies became visible soonest; and reached the greatest maximum size. The superiority of this medium was particularly evident with inocula of BCG reconstituted after freeze-drying.

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