Biochemical effects of irradiated sucrose solutions in the rat

Abstract

The in vitro and in vivo effects of irradiated sucrose solutions on some enzyme systems in rats have been investigated. A fraction derived from irradiated sucrose solution and reportedly cytotoxic to cell cultures has been observed to inhibit succinate oxidation and coupled phosphorylation by rat liver mitochondria in vitro. Lipid, protein, and DNA synthesis, as evidenced by incorporation of isotopically labeled precursors, are also inhibited in vitro, presumably as a result of primary impairment of oxidative phosphorylation and hence of the formation of ATP. The toxicity exhibited by irradiated sucrose solution is considerably reduced when irradiation is carried out under nitrogen or in the frozen state or in a buffered condition at neutral pH. Autoclaved sucrose solutions exhibit similar in vitro toxicity toward oxidative metabolism, but there appear to be qualitative differences between the degradation products due to radiolysis and heat-treatment. Assessed by various parameters, no deleterious effects could be observed in rats fed the irradiated sucrose solution for a period of 8 weeks. Studies with sucrose-U-¹⁴C indicate that the products of radiolysis when orally administered to rats are rapidly metabolized and excreted with no detectable retention in the tissues of the animal beyond 30 hours.