Ultrastructural changes in liver damage induced by carbon tetrachloride in spontaneously hypertensive rats and Wistar-Kyoto rats.

The effects of carbon tetrachloride (CCl4) on the liver in spontaneously hypertensive rat (SHR) and Wistar-Kyoto rat (WKY) were investigated ultrastructurally in this study. Repetition of CCl4 treatment twice a week for four weeks, revealed liver cirrhosis in SHR, whereas, only bridging fibrosis was observed in the WKY, histologically, by reticulin silver impregnation. Scanning electron microscopy revealed that the liver surface of SHR was irregularly nodulated, while it was relatively smooth in case of the WKY. Transmission electron microscopy revealed that the mitochondria cristae were peripherally located in both strains. Vesicular change of the rough endoplasmic reticulum was observed to be more severe in SHR than in WKY. Further, local hypertrophy of the smooth endoplasmic reticulum and large lipid droplets were more easily observed in WKY than in SHR. The present results hence indicate that chronic chemical CCl4 intoxication induces severe ultrastructural organelle damage in hypertensive rats, leading to liver cirrhosis. On the other hand, CCl4 induced fatty liver and a relatively mild fibrosis were observed in normotensive rats. These findings suggest that the liver ultrastructural organelles are more susceptible to CCl4 in SHR than in WKY.