Effect of n-hexane inhalation on insulin degradation in rat blood in vitro

Effect of inhalation of an air-n-hexane mixture on insulin degradation in rat blood in vitro was studied under simultaneous monitoring of n-hexane concentrations in blood (using gas chromatography) and in the inhaled air (using infrared analysis). Inhalation of n-hexane vapours in a concentration of 54,694 +/- 1933 ppm (197 +/- 7 g m-3) resulted in blood n-hexane saturation within 15 min. (0.18 +/- 0.023 mg ml-1) associated with a statistically increased (P less than 0.002) insulin degradation in the blood of exposed rats as compared to control animals 0.152 +/- 0.03 vs. 0.053 +/- 0.003). To rule out possible effects of stress on the results obtained, effects of both, 20 min restraint stress (RS) and equally long handling (HAN) on insulin degradation were also estimated. The data thus obtained were compared with insulin degradation in control (C) rats which were killed by decapitation in the animal room. No significant differences were observed between the individual groups (C: 0.055 +/- 0.08; RS: 0.068 +/- 0.01; HAN: 0.069 +/- 0.015). In vitro addition of n-hexane to pure plasma or to a mixture of blood elements revealed that degradation activities present in the cellular blood compartment are required for the n-hexane-induced enhancement of insulin degradation in the blood to occur.