Changes of blood fluidity in the early hepatopathy in rats.

The present study was designed to examine the influence of the early stage hepatopathy on blood fluidity by using a rat experimental system. F344 male rats, 4 weeks of age, were fed chow containing 3'-methyl-4-dimethylaminoazobenzene (DAB) at 0.06%. These rats were autopsied 8, 12, 16 and 20 weeks after starting DAB feeding. Blood samples were collected from the inferior vena cava under pentobarbital anesthesia and blood fluidity and platelet aggregation activity were examined by a Micro Channel Array Flow Analyzer and a platelet aggregometer, respectively. We also examined histological changes in the liver after staining with hematoxylin-eosin. Histological observation of the liver revealed early-stage hepathopathy when the organs were obtained from rats that fed DAB for more than 16 weeks. Although DAB-feeding of rats for 8 and 12 weeks barely affected blood fluidity, long-term intake (>16 weeks) caused decrease in fluidity. On the other hand, platelet aggregation activity was increased when rats were fed DAB for more than 16 weeks. The present results suggest that assaying for blood fluidity may be useful for the assessment of the degree of hepatopathy.