Effects of dicentrine on the mechanical properties of systemic arterial trees in dogs.

We evaluated the effects of dicentrine on the physical properties of systemic arterial trees. Dicentrine, isolated from Lindera megaphylla, was identified as a potent, selective alpha 1-adrenoceptor antagonist. We used high-fidelity multisensor catheter to measure the ascending aortic pressure and flow signals in 9 mongrel dogs. A succinct T-tube model with vascular nonuniformity was adopted to relate the pulsatile pressure and flow waves. The model-estimated parameters were capable of representing the mechanical properties of the blood vessel walls. Dicentrine had a beneficial effect on the rigidity of head and body circulation, respectively. There were great improvements not only in the tube distensibility and wave transmission time, but also in the peripheral load compliance and resistance. In global circulation that was defined as the parallel combination of head and body circulation, dicentrine significantly reduced values in characteristic impedance of the ascending aorta from 164 +/- 67 to 105 +/- 43 dynes/s/cm5, and in wave reflection factor from 0.46 +/- 0.14 to 0.36 +/- 0.13, and in total peripheral vascular resistance from 4,751 +/- 1,226 to 3,581 +/- 1,277 dynes/s/cm5. On the other hand, total peripheral load compliance was increased from 0.2950 +/- 0.1794 to 0.4457 +/- 0.2199 ml/mm Hg. Cardiac output (CO) and heart rate (HR) remained unchanged, however. Dicentrine had an impact on the mechanical properties of Windkessel vessels and resistance vessels in the systemic circulation.