TABLE 1

PDE isoenzyme selectivity of BRL 50481

cAMP/cGMP Concentration Inhibition of Cyclic Nucleotide Hydrolysis (IC50)
hrPDE7A1 PDE1Ba PDE1Ca PDE2a PDE3a hrPDE4A4 PDE5a
μM
BRL 50481
0.05 μM 0.26 >100 >100 >100 490 62 >100
1 μM 2.4 >100 >100 >100 >1000 92 >100
IBMX
0.05 μM 5.7 N.D. N.D. N.D. 0.87 11 N.D.
1 μM 53 N.D. N.D. N.D. 5.1 14 N.D.
Siguazodan
0.05 μM >1000 N.D. N.D. N.D. 0.25 >1000 N.D.
1 μM >1000 N.D. N.D. N.D. 1.1 >1000 N.D.
Rolipram
0.05 μM 280 N.D. N.D. N.D. 300 0.07 N.D.
1 μM >1000 N.D. N.D. N.D. >1000 0.17 N.D.
  • N.D., not determined.

  • a Isozymes purified from canine trachealis.