ts 155-2, is a macrocyclic lactone related to hygrolidin, is produced by a different streptomyces species found in oil. it blocks thrombin-evoked calcium (ca2+) entry into cells. ts155-2 exerts hypotensive, anti-platelet, anti-ischaemic and anti-inflammatory activity showed on the original patent, however, no literature investigation of ts155-2 is available.a rapid increase in cytosolic ca2+ is related to the signal transduction events following the induction of thrombin in a wide range of cell types which include fibroblasts, platelets, megakaryocytes, endothelium and smooth muscle. thrombin-stimulated ca2+ mobilization has been shown to be involved in both ca2+ release from internal storage sites and ca2+influx and has been extensively studied in human platelets. thrombin triggers phospholipase c resulting in the rapid generation of inositol 1,4,5-trisphosphate (ip3), which elicits the release of ca2+ from ip3-sensitive stores. however, the thrombin-induced ca2+ influx is still an area of contention [1].
[1]. somasundaram, b., mason, m., & mahaut-smith, m. thrombin-dependent calcium signalling in single human erythroleukaemia cells. the journal of physiology.1997;501(3):485-495.
