Hepatic microcirculation in Zucker fatty rats.

We have developed a microscopic analyzing system for studying in vivo hepatic microcirculation, and measured the sinusoidal erythrocyte flow velocity simultaneously in the various sinusoids. With this system and organ reflectance spectrophotometry, the pathophysiological role of microcirculation and of energy metabolism in Zucker fatty rats were studied. The results were as follows: The erythrocyte flow velocity in the predominant sinusoids in the fatty rats was similar to that of the control rats, but the intersinusoidal erythrocyte flow was undetected in the fatty liver. Index of regional hepatic blood volume, regional hepatic blood flow and oxygen saturation of Hb decreased significantly in the fatty rats. The estimated in vivo oxygen consumption was not changed in the fatty liver. From these data, it is concluded that in Zucker fatty rats a marked fatty infiltration causes a decreased hepatic tissue blood flow and volume, but relatively homogeneous erythrocyte flow with an increased extraction of oxygen compensated the decreased vascular beds and maintained normal energy metabolism.