ICI 153110

ICI 153110 is an orally active phosphodiesterase inhibitor with both vasodilating and inotropic properties which is designed for the treatment of congestive cardiac failure. Fourteen animals have died as a direct or indirect consequence of ICI 153110 administration in the high-dose main test and reversibility groups. In the female rat dosed at 10 mg/kg/day ICI 153110 a mild focal arteritis is characterized by a predominantly and diffusely adventitial infiltration of mixed cells and early formation of fibrous tissue. The two rats dosed at 250 mg/kg/day ICI 153110 die prematurely from intratracheal intubation of dosing solution. Arteries from two further animals (dosed at 5 and 250 mg/kg/day ICI 153110) show minimal focal arteritis with medial necrosis, and medial and adventitial inflammation^[1].