Determination of the formation of thromboxane B2 (TxB2), 12L-hydroxy-5,8,10 heptadecatrienoic acid (HHT) and 12L-hydroxy-5,8,10,14 eicosatrienoic acid (HETE) from arachidonic acid and of the TxB2 :HHT, TxB2 :HETE and (TxB2 +HHT) :HETE ratio in human platelets. Possible use in diagnostic purposes.

The formation of thromboxane B2 (TxB2), 12L-hydroxy-5,8,10 heptadecatrienoic acid (HHT) and 12L-hydroxy-5,8,10,14 eicosatrienoic acid (HETE) was determined in the platelets of normal human males and of patients with disorders in which an abnormal platelet aggregation occurs. Platelets were labelled with [1-14C] arachidonic acid. After Aggregation and extraction the metabolites wee separated by TLC and determined. In the platelets of normal males, TxB2 values were in the range 4.4-12.4%, expressed as a percentage of total radioactivity. Curves were constructed for the following ratios: TxB2 :HHT, TxB2 :HETE and (TxB2 + HHT) :HETE. These ratios were fairly contant. A comparison was made with the ratios obtained in the platelets of a small number of patients with either an enhanced or a diminished aggregation.