In order to study the effect of dihydroxyacetophenone (DHAP) on pulmonary hemodynamics and its relationship to plasma atrial natriuretic peptide (ANP) as well as adenosine cyclophosphates in chronic obstractive pulmonary disease (COPD)

right heart catheterization was used to examine some parameters of hemodynamics in 11 COPD patients before and after the application of DHAP

and at the same time radioimmunoassay was used to measure the plasma ANP and cyclo-adenosine monophosphate/cyclic guanosine monophosphate (cAMP/cGMP). The results showed that DHAP 640 mg given intravenously could decrease mean pulmonary arterial pressure

pulmonary vascular resistance and systemic vascular resistance (P < 0.05)

but increase cardiac output from 4.10 ±1.08 L/min to 5.13 ±1.19 L/min (P>0.05) and without affecting systemic arterial blood pressure (P>0. 05) as well as blood gas analysis; it could also reduce the plasma ANP and cGMP level from 0.73 ± 0.42 pg/ml to 0.41 ±0.33 pg/ml (P<0.01) and from 9.82 ±5.75 pm/ml to 8.01 ± 4.80 pm/ml(P<0.05) respectively

but did not affect the plasma cAMP level (P>0.05). It is suggested that DHAP may relax pulmonary vessels by adjusting the ratio of cAMP to cGMP

and the lowering of plasma ANP level might be a secondary reaction. So DHAP was considered a quick-acting

safe and potential drug in treating pulmonary arterial hypertension by COPD.