Development of a servo pump system for in vivo loading of pathological pulmonary artery impedance on the right ventricle of normal rats

作者：Fukumitsu Masafumi; Kawada Toru; Shimizu Shuji; Turner Michael J; Uemura Kazunori; Sugimachi Masaru^*

来源：American Journal of Physiology - Heart and Circulatory Physiology, 2016, 310(8): H973-H983.

DOI：10.1152/ajpheart.00813.2015

• pulmonary hypertension
• pulmonary artery impedance
• monocrotaline
• windkessel model

Pulmonary artery (PA) impedance provides detailed information on right ventricular (RV) afterload in pulmonary hypertension (PH). This study aimed to examine PA impedance in a rat model of monocrotaline-induced PH (MCT-PH) and to develop an experimental system for in vivo loading of pathological PA impedance on the RV of normal rats. PA impedance was quantified in normal (n = 10) and MCT-PH rats (n = 10) using a three-element Windkessel (3-WK) model. Compared with normal rats, MCT-PH rats had higher characteristic impedance (Z(C)) and peripheral pulmonary resistance (RP) (ZC: 0.121 +/- 0.039 vs. 0.053 +/- 0.017 mmHg.min.ml(-1), P < 0.001; RP: 0.581 +/- 0.334 vs. 0.252 +/- 0.105 mmHg.min.ml(-1), P = 0.013) and lower pulmonary artery compliance (C-P) (0.242 +/- 0.131 vs. 0.700 +/- 0.186 ml/mmHg, P < 0.001). In another group of 10 normal rats, a computer-controlled servo pump was connected to the left PA for loading PA impedance with parameters in pathological ranges designed by the 3-WK model. Activation of the servo pump decreased the error of measured vs. target PA impedance (modulus: from 0.047 +/- 0.020 without pump activation to 0.019 +/- 0.007 with pump activation, P < 0.001; phase: 0.085 +/- 0.028 to 0.043 +/- 0.012 radians, P < 0.001). In conclusion, MCT-PH increases ZC and RP and decreases CP. Our servo pump system, which is capable of imposing arbitrary PA impedance with pathological parameters, may offer a unique opportunity to delineate the pathological significance of PA impedance in PH.

• 出版日期2016-4-15