[Experimental study on aldolase isozyme during the development of hepatoma in the rat (author's transl)].

Aldolase (ALD) consists of three different types of isozyme, i.e. muscle or A type, liver or B type and brain or C type, their relative proportions being fixed for each tissue. In this study, isozyme profiles in the serum and DAB induced hepatoma as it grows were examined in comparison with those in the fetal liver, in the hope to obtain information for early detection of the malady. In the very early phase of hepatoma growth with no elevated enzyme activity, ALD-A fraction after electrophoresis was found to increase. In the course of hepatoma growth, ALD-B decreased while ALD-A increased with appearance of hybrid of ALD-A and ALD-C. In the normal adult liver, no hybrid of ALD-A and ALD-C was encountered. Serum profile of the rat with DAB induced hepatoma was similar to that of the cancer tissue. On the other hand, the fetal liver shows a profile with high ALD-A fraction and even with hybrid of ALD-A and -C. These features disappeared gradually as maturation proceeded and became close to the adult pattern. Thus it is clear that DAB induced hepatoma exhibits retrogressive change in hepatic differentiation in its isozyme profile. The results also indicate usefulness of isozyme profile for early detection of the hepatoma.