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Assessing Cerebral Autoregulation via Oscillatory Lower Body Negative Pressure and Projection Pursuit Regression
11:26

Assessing Cerebral Autoregulation via Oscillatory Lower Body Negative Pressure and Projection Pursuit Regression

Published on: December 10, 2014

Hepatic arterial pressure-flow autoregulation is adenosine mediated

W R Ezzat, W W Lautt

    The American Journal of Physiology
    |April 1, 1987
    PubMed

    Insights

    Adenosine plays a key role in hepatic artery (HA) autoregulation and the hepatic arterial buffer response (HABR). Adenosine antagonists inhibit both HA vasodilation and autoregulation, suggesting a shared mechanism.

    Area of Science:

    • Physiology
    • Cardiovascular Research
    • Hepatic Circulation

    Background:

    • Hepatic artery (HA) autoregulation is crucial for maintaining liver blood flow.
    • The hepatic arterial buffer response (HABR) involves HA vasodilation in response to reduced portal flow.
    • The role of adenosine in these processes has been investigated.

    Purpose of the Study:

    • To investigate the role of adenosine in hepatic artery (HA) pressure-flow autoregulation.
    • To evaluate the effect of adenosine antagonists on HA autoregulation and the hepatic arterial buffer response (HABR).
    • To elucidate the underlying mechanism of HA autoregulation and HABR.

    Main Methods:

    • Quantifying pressure-flow autoregulation in the feline HA.
    • Administering selective adenosine antagonists (8-phenyltheophylline and 8-(p-sulfophenyl)theophylline).
    • Evaluating vasodilator responses to exogenous adenosine and the HABR.

    Main Results:

    • Weak pressure-flow autoregulation was observed in the HA of cats.
    • Adenosine antagonists inhibited both HA autoregulation and the vasodilator response to adenosine.
    • These antagonists also inhibited the HABR.

    Conclusions:

    • The findings suggest that local adenosine levels influence HA pressure-flow autoregulation.
    • The mechanism of HABR is proposed to involve adenosine washout into portal blood.
    • HA pressure-flow autoregulation and HABR likely share a common mechanism involving adenosine washout.

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