PDF icon Download PDF
Thromb Haemost 1984; 51(02): 140-144
DOI: 10.1055/s-0038-1661045
Original Article
Schattauer GmbH Stuttgart

Effects of Tris on Responses of Human and Rabbit Platelets to Aggregating Agents

M A Packham
The Department of Biochemistry, University of Toronto, Toronto, and Department of Pathology, McMaster University, Hamilton, Ontario, Canada
,
M A Guccione
The Department of Biochemistry, University of Toronto, Toronto, and Department of Pathology, McMaster University, Hamilton, Ontario, Canada
,
M Nina
The Department of Biochemistry, University of Toronto, Toronto, and Department of Pathology, McMaster University, Hamilton, Ontario, Canada
,
R L Kinlough-Rathbone
The Department of Biochemistry, University of Toronto, Toronto, and Department of Pathology, McMaster University, Hamilton, Ontario, Canada
,
J F Mustard
The Department of Biochemistry, University of Toronto, Toronto, and Department of Pathology, McMaster University, Hamilton, Ontario, Canada
› Author Affiliations
Further Information

Publication History

Received 29 September 1983

Accepted 03 September 1983

Publication Date:
19 July 2018 (online)

 PDF Download  Permissions and Reprints
Preview

Summary

Despite reports that Tris [tris(hydroxymethyl)aminomethane] affects platelets, it is often used to buffer suspending media. Human or rabbit platelets were washed and resuspended in Tyrode solution containing apyrase and 0.35% albumin. Addition of 15 mM Tris partially inhibited primary aggregation induced by 10 μM ADP and inhibited aggregation and release of 14C- serotonin from prelabelled platelets stimulated with low concentrations of thrombin (0.05-0.2 U/mL), or collagen. Platelets resuspended in 15 mM Tris, 0.15 M NaCl, 0.35% albumin, pH 7.5, did not aggregate in response to 10 μM ADP whereas platelets in Tyrode-albumin aggregated extensively. Ca2+ (5 mM) did not overcome the inhibition of thrombin-induced aggregation. Tris (15 or 1.5 mM) potentiated aggregation and release induced by sodium arachidonate (20-50 μM) or the ionophore A23187 (0.6-1 μM). Pretreatment of platelets with aspirin did not prevent potentiation by A23187, indicating that it is not mediated through activation of the arachidonate pathway. The inhibitory and potentiating effects of Tris are similar to those of amino sugars, lysine, arginine and primary amines such as methylamine and cadaverine, and may represent general effects of amines on platelets. Potentiation of the effects of some aggregating agents and inhibition of others re-emphasizes the concept that there are several different mechanisms through which aggregation can occur. Tris-based buffers are unsuitable for platelet suspending media and their use as solvents for aggregating agents or inhibitors should be limited.

Keywords

Tris - Platelet aggregation - Platelet suspending media - Platelet inhibitor - Potentiation of platelet aggregation