The interaction of topically applied toluene and ambient temperature on O₂ uptake of tissue homogenates

These studies examined the role of toluene in temperature-cancer experiments where it was used as a solvent for benzo(a)pyrene (BaP). Toluene (0.08 ml/wk topically) and ambient temperature (cool T(a) = 16°C, normal T(a) = 23°C and warm T(a) = 32°C) interacted to affect O₂ uptake of tissue homogenates. After 3.5 weeks of acclimation and 2 weeks of toluene (0.16 ml total), O₂ uptake of muscle homogenates was elevated 32% for all T(a)'s; O₂ uptake of skin homogenates was elevated 139% for all T(a)'s; however, O₂ uptake of liver homogenates was elevated 665% in cool T(a), elevated 36% in normal T(a) but depressed 50% in warm T(a). The pattern of liver homogenate O₂ uptake of C>N>W is similar to that for tumorigenesis when BaP is dissolved in the toluene, although toluene alone is nontumorigenic. Common cellular mechanisms may be involved in the metabolism of toluene, the activation of BaP and in thermogenic acclimation.