Adenosine Diphosphate‐induced Platelet Aggregation in Suspensions of Washed Rabbit Platelets

Abstract

A method is described for the preparation of suspensions of washed rabbit platelets which will aggregate upon the addition of low concentrations of ADP that are effective in citrated plasma. This method involves collecting blood into ACD, low pH, removal of calcium, and maintenance of magnesium during the isolation procedure. A protein (albumin) and glucose are included in the washing and suspending solutions. Rabbit platelets prepared in this way retained fibrinogen on their surface. On comparison with rabbit platelets prepared from blood taken into EDTA, the only differences observed were the much greater sensitivity to ADP and a higher calcium content ; platelet morphology, nucleotide levels, and conversions of 14C-ATP and 14C-ADP at the platelet membrane were similar.

Concurrent measurement of the survival of two populations of rabbit platelets labeled with either two PKH lipophilic dyes or two concentrations of biotin

“…Suspensions of washed platelets were prepared at 23°C by the method of Ardlie et al (22,23). For biotin labeling, in the first washing step, platelets that had been recovered from platelet-rich plasma by centrifugation were suspended in calcium-free Tyrode's solution containing 0.52 mM EGTA and 0.35% albumin, pH 6.5 (one half volume of the original whole blood-ACD mixture).…”

Leukocyte-Dependent Histamine Release From Rabbit Platelets

“…The most likely explanation of these observations is that the basophils release a factor that diffuses quickly into the medium to bind to leukocytes and platelets, thus creating conditions for diffuse and nonspecific aggregation. This would explain why in the literature the morphology of letLkocytes adherent to platelet aggregates varies from that corresponding to the small lymphocyte (14) to that resembling the monocyte (17), which are the cell types predominant in rabbit buffy coat preparations.…”

“…Platelets.--Adult New Zealand white rabbits were bled from the ear artery into acid citrate dextrose (ACD) (16) or 5 X 10 .3 ]~ ethylenediaminetetraacetate (EDTA), pH 7.2, and platelets were obtained by a modification of the method of Ardlie et al (17). Blood centrifuged at room temperature at 400 g for 20 rain separated into three layers: the plateletrich plasma layer, which was removed; the buffy coat layer, which was processed as described below; and the erythrocyte and neutrophil layer, which was discarded.…”

Isolation of plasma co‐factor in adenosine diphosphate‐induced aggregation of bovine platelets

“…Bang et al [3] reported that fibrinogen, Hageman factor and gamma globulin in human blood are capable of restoring aggregation capability of washed human platelets. Ardlie et al [4] demonstrated that ADP-induced aggregation of washed platelets from rabbit blood occurs in modified Tyrode's solution containing bovine serum albumin.…”