Effects of Lipochromin and Levosinum in the modulation of radiation-induced injury to pig skin

Pig skin was used as a model to study the effectiveness of two topically ap plied creams, Lipochromin and Levosinum, in modifying the development of bo th early and late radiation damage to pig skin. Irradiated skin sites that received daily topical application of Levosinum or Lipochromin after exposu re were compared with sites on the contralateral flank of the same animal t hat received irradiation only. Irradiation was with graded doses of Sr-90/Y -90 beta-rays. Incidence of moist desquamation (acute) and ischaemic dermal necrosis (late) were used as endpoints. The latency period for the develop ment of moist desquamation and its healing time was also assessed. The late ncy period for the development of moist desquamation in this model ranged f rom 4.00-6.75 weeks. There was no significant difference between the cream treatment and control sites. Application of Levosinum shortened the healing time of moist desquamation at each dose level by 5-10 days. In three out o f four dose levels used, this shortening of the healing time was statistica lly significant (p<0.03). Treatment with these topical applications also re duced the incidence of late dermal necrosis and increased the ED50 values f or the incidence of dermal necrosis. This increase in ED50 values was equiv alent to a dose modification factor of 1.11-1.13.