BRL-50481 is a drug developed by GlaxoSmithKline which is the first compound that acts as a

phosphodiesterase inhibitor A phosphodiesterase inhibitor is a drug that blocks one or more of the five subtypes of the enzyme phosphodiesterase (PDE), thereby preventing the inactivation of the intracellular second messengers, cyclic adenosine monophosphate (cAMP) and cyc ...

selective for the PDE7 family. PDE7 activity is encoded by two genes,

PDE7A High affinity cAMP-specific 3',5'-cyclic phosphodiesterase 7A is an enzyme that in humans is encoded by the ''PDE7A'' gene. Mammals possess 21 cyclic nucleotide phosphodiesterase (PDE) genes that are pharmacologically grouped into 11 families. PD ...

and

PDE7B PDE7B is a mammalian gene that encodes a 3'5'-cyclic nucleotide phosphodiesterase (PDE) that converts 3'5'-cyclic adenosine monophosphate (cAMP) to 5'AMP as part of cyclic nucleotide signaling pathways.Sasaki, T., Kotera, J., Yuasa, K., and Omori, ...

. BRL-50481 actually shows about an 80-fold preference for the PDE7A subtype, for which it was developed, over PDE7B. BRL-50481 has been shown to increase mineralisation activity in osteoblasts, suggesting a potential role for PDE7 inhibitors in the treatment of osteoporosis.

References

{{Phosphodiesterase inhibitors PDE7 inhibitors Sulfonamides Nitrobenzene derivatives Experimental drugs 2-Tolyl compounds 4-Tolyl compounds