Survey of some enzyme patterns in transplantable Reuber mouse hepatomas.

by injections of hormones6 (20), by theophylline,6 or by adrenalectomy6 (20). These studies have emphasized the diversity of enzyme patterns and adaptive responses present in transplantable rat hepatomas with a wide spectrum of growth rates (6). Recently, a series of transplantable mouse hepatomas of spontaneous origin has been developed, the occurrence of which was first reported by Andervont and McEleney (1) in 1941, using C3H inbred mice. Subsequent studies confirmed their observation (5) and noted an increased incidence of hepatomas in C3H X Y hybrid mice over that observed with C3H mice (3, 4). Hancock and Dickie (2) have reported the occurrence of spontaneously arising hepatomas in (DBA/2WyDi X CE/J) @ male mice fed a high-fat diet but developed only one transplantable line from the spontaneous hepatomas. Several of the spontaneously occurring hepatomas in C3H X Y mice have now been transplanted serially, and enzyme activities have been determined for tyrosine aminotransferase (EC 2.6.1.5), SDH,7 G6PDH, and CCE. The availability of the series of Reuber mouse hepatomas and of the series of Morris rat hepatomas may allow a detailed investigation of the diversity of enzyme patterns not only between 2 species of laboratory animals but also between spontaneously arising and chemically induced transplantable hepatomas.