[Inhibition of cyclic nucleotide phosphodiesterase from rabbit heart by hydroxypyridines]

3-Hydroxypyridines, which are inhibitors of cyclic nucleotide phosphodiesterase, affected reversibly and non-competitively the enzyme molecule as compared with cAMP. A number of substances was found exhibiting high inhibitory and antioxidant activities, high inhibitory and low antioxidant activities, as well as low inhibitory and high antioxidant activities. Elucidation of the 3-hydroxypyridines action via antioxidant or phosphodiesterase pathways became possible.