Abstract
Thromboxane A2 (TxA2) is a potent platelet aggregator as well as a vascular and bronchial constrictor. DP-1904, a newly synthesized imidazol TxA2 synthetase inhibitor, is a potent and long-acting agent.
The present investigation was conducted to explore the effect of DP-1904 on the contractile responses in rabbit pulmonary artery and descending aorta strips induced by various vasoactive substances.
Fourteen Japanese albino rabbits, weighing about 3kg, were sacrificed. Rabbit pulmonary artery and descending aorta were removed, cut spirally, set up in bioassay glass jackets and superfused with Krebs-Henseleit solution at 37°C, saturated with oxygen and carbon dioxide. Contraction of tissues was detected by an isotonic transducer and displayed on a polyrecorder.
Arachidonic acid-induced contractile responses in rabbit pulmonary artery and descending aorta strips were attenuated significantly by the continuous infusion of DP-1904 in a dose-dependent fashion.
Prostaglandin F2α-induced contractile responses in rabbit pulmonary artery and descending aorta strips were attenuated significantly by the continuous infusion of DP-1904, dose-dependently.
Angiotensin II-induced contractile responses in rabbit pulmonary artery and descending aorta strips were attenuated significantly by the continuous infusion of DP-1904, dose-dependently.
Norepinephrine-induced contractile responses in rabbit pulmonary artery and descending aorta strips were attenuated significantly by the continuous infusion of DP-1904, dose-dependently.
The above results suggest that DP-1904 might be a useful therapeutic agent for the treatment of pulmonary hypertension in patients with chronic obstructive lung diseases.
