Pyr3, a pyrazole compound, selectively inhibits the canonical transient receptor potential channel 3 (TRPC3) [1].?

TRPC3 is a member of TRPCs which control influxes of Ca²⁺ and other cations that induce diverse cellular processes upon stimulation of plasma membrane receptors coupled to phospholipase C. TRPC3 has been implicated in diverse biological functions, including B cell receptor-mediated Ca²⁺ oscillations, T cell receptor-dependent Ca²⁺ entry pathway, and cardiac hypertrophy [1].?

In HEK293 cells, Pyr3 selectively inhibited TRPC3-mediated Ca²⁺ influx in a dose-dependent manner, with an IC50 value of 0.7 μM. In rat neonatal cardiomyocytes, Pyr3 suppressed activation of nuclear factor of activated T cells, with an IC50 value of 0.05 μM [1].?

In sham operated mice, chronic treatment with Pyr3 (0.1 mg·kg^?1·day^?1, i.p.), Pyr3 attenuated in vivo pressure overload-induced cardiac hypertrophy. In addition, the transverse aortic constriction operation-induced increase in expression of atrial natriuretic peptide mRNA, a reliable marker for cardiac hypertrophy, was also suppressed by Pyr3 [1].?

Reference:

[1]. Kiyonaka S, Kato K, Nishida M, et al. Selective and direct inhibition of TRPC3 channels underlies biological activities of a pyrazole compound. Proceedings of the National Academy of Sciences of the United States of America, 2009, 106(13): 5400-5405.