Radiosensitivity of mouse lip mucosa: Influence of anesthesia, carbogen, and a new high O₂ carrying perfluorochemical emulsion

The effect of a new perfluorochemical emulsion based on F-66E (54%, w/v) which carries, in combination with carbogen, twice as much oxygen as Fluosol-DA 20% was tested on the radiation response of the lip mucosa of unanesthetized mice. Mice were pretreated with 0.015 ml/g of the F-66E emulsion in the presence of carbogen for 1 h prior to and during irradiation. There was a significant increase in the mortality rate following the highest radiation dose in mice given F-66e emulsion plus carbogen. The reactions of lip mucosa of mice given F-66E emulsion and/or carbogen were not significantly different from that of the control group using three end points (average score, mean peak, incidence of mucosal desquamation), but the peak mucosal reaction was delayed. The radiosensitivity of the mouse lip mucosa to Ethrane, an anesthetic gas inhaled with carbogen, was also tested. The reaction of lip mucosa in the anesthetized mice was significantly greater than that of the control group. There was also a significant increase in the mortality rate following the two highest radiation doses.