Activity of a purified nonsteroidal gametic factor on the inducibility of hepatic delta-aminolevulinic acid synthetase, NADPH-oxidase and tyrosine aminotransferase in senescent rats.

The effect of a water soluble nonsteroidal factor extracted from the male gamete on the activity of certain liver inducible enzymes during aging has been examined. Three enzymes have been studied: delta-aminolevulinic acid synthetase, NADPH-oxidase and tyrosine aminotransferase whose inducibility by ethanol, phenobarbital and ACTH, respectively, show age dependent alterations. The results here reported show that this factor is able to restore the enzyme inducibility in the liver of aging (600-day-old) rats without affecting the response of young (40-day-old) rats. Since the enzyme inducibility is altered during aging, and in the majority of rat hepatomas this factor might enter, possibly, in the regulation of enzyme activity also of neoplastic cells.