Assessment of Systemic and Regional Blood Flows with the Radioactive Microsphere-Reference Sample Method in Rats

  • Jin Yamamoto
  • Masatsugu Nakai


The radioactive microsphere-reference sample (RMRS) method has become applied to hemodynamic studies even in small animals such as rats [1, 2]. The assumptions and prerequisites of this method in determining systemic and regional blood flows have been described previously [1–3]. Cardiac output and regional blood flow can be obtained by determining the amount of the radioactivity injected and that of the reference sample withdrawn at a known rate and then by comparing them with the radioactivity entrapped by regional organs. The accuracy and precision of this technique are influenced by many factors, including the number of microspheres injected, the site of injection, the rate of reference blood withdrawal, and the kind of suspension agents [1–7]; however, appropriate experimental conditions seem to be now established in rats [2, 6, 7]. In comparison with an independent method, Ishise et al. demonstrated that cardiac output determined by the RMRS method correlated excellently with that determined simultaneously by electromagnetic flowmetry in rats [2].


Cardiac Output Mean Arterial Pressure Sodium Nitroprusside Regional Blood Flow Splanchnic Blood Flow 
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Copyright information

© Springer-Verlag Tokyo 1988

Authors and Affiliations

  • Jin Yamamoto
    • 1
  • Masatsugu Nakai
    • 1
  1. 1.Department of Cardiovascular Dynamics and FunctionNational Cardiovascular Center Research InstituteSuita, Osaka, 565Japan

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