A series of thieno [2, 3-c] pyridine antagonists of cell adhesion molecule (CAM) expression, such as A-205804 (1) and A-249377 (2), selectively suppressed the induced expression of E- selectin and ICAM-1 over VCAM-1. In an effort to explore the biological mechanism of action of these inhibitors, we synthesized 125I-and 3H-labeled thieno [2, 3-c] pyridines 5 and 6. An isolated diazonium tetrafluoroborate salt efficiently trapped Na125I on very small scale ( ...