Lewy R I, Smith J B, Silver M J, Saia J, Walinsky P, Wiener L
Prostaglandins Med. 1979 Apr;2(4):243-8. doi: 10.1016/0161-4630(79)90059-4.
The plasma levels of thromboxane B2 (TxB2) were determined by radioimmunoassay in 6 consecutive patients with Prinzmetal's angina and in 9 healthy volunteers. In the normal group TxB2 was not detectable (= 0.5 pmoles/ml), while in patients with variant angina TxB2 was consistently detected (1.5-140 pmole/ml).