Table 1: The IC_{50} and K _{i} (M) values of S-petasin and reference drugs on PDE isozymes 1–5. | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||

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All values are expressed as the mean ± SEM (n), and n is the number of experiments. ND, not determined.^{
a}Reference drugs for PDE isozymes 1, 2, 3, 4 and 5 were vinpocetin, EHNA, milrinone, Ro 20-1724 and zaprinast, respectively., compared to the corresponding value of PDE3. |