EFFECTS OF DICENTRINE ON THE MECHANICAL-PROPERTIES OF SYSTEMIC ARTERIAL TREES IN DOGS

We evaluated the effects of dicentrine on the physical properties of s ystemic 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 o f representing the mechanical properties of the blood vessel walls. Di centrine had a beneficial effect on the rigidity of head and body circ ulation, respectively. There were great improvements not only in the t ube distensibility and wave transmission time, but also in the periphe ral load compliance and resistance. In global circulation that was def ined as the parallel combination of head and body circulation, dicentr ine significantly reduced values in characteristic impedance of the as cending aorta from 164 +/- 67 to 105 +/- 43 dynes/s/cm(5), and in wave reflection factor from 0.46 +/- 0.14 to 0.36 +/- 0.13, and in total p eripheral vascular resistance from 4,751 +/- 1,226 to 3,581 +/- 1,277 dynes/s/cm(5). On the other hand, total peripheral load compliance was increased from 0.2950 +/- 0.1794 to 0.4457 +/- 0.2199 ml/mm Hg. Cardi ac output (CO) and heart rate (HR) remained unchanged, however. Dicent rine had an impact on the mechanical properties of Windkessel vessels and resistance vessels in the systemic circulation.