we studied the action of the following phosphodiesterase inhibitors ( pdeis ) : rolipram ( 4- [ 3-cyclopentoxy-5-methoxyphenyl ] -2-pyrrolidione ) , ro 20-1724 ( 4- [ 3-butoxy-4-methoxybenzyl ] -2-imidazolidione ) , 1-methyl-3-isobutylxanthine ( imbx ) and theophylline on flexor reflex activity of the hind limb in the spinal rat .
C0000096
1-methyl-3-isobutylxanthine
C0039771
theophylline