Release of Marker Lysosomal Enzymes by 3-Methylindole and Indole from Rabbit Lung Lavage Cells 1

Summary

Rabbit lung lavage cells (LLC) were incubated with 0, 200, 300, and 400 ppm (0, 1.53, 2.29, and 3.05 mM) of 3-methylindole (skatole, 3MI) or 0, 400, 600, and 800 ppm (0, 3.42, 5.13, and 6.84 mM) of indole for up to 4 hr at 37°. The release of βgalactosidase and βglucuronidase activities was compared to the total enzyme activity solubilized by sonication. Significant increases in soluble enzyme activity were obtained with these concentrations of 3MI, and the amount of enzyme activity solubilized depended upon the 3MI concentration and incubation time. After incubation with 400 ppm of 3MI for 4 hr, 58% of the total βgalactosidase and 46% of the βglucuron-idase activities was solubilized from LLC. This activity was greater than that released by freezing and thawing two times. At higher concentrations, indole caused a similar release of these lysosomal enzyme activities. Significantly more βgalactosidase activity was released when LLC were incubated with 3MI in combination with low concentrations of acetylsalicylic acid, reti-noic acid, Triton X-100, and phosphatidyl serine than by incubation with each agent alone. Incubation with DMSO decreased enzyme release by 3MI, and 3MI inhibited some of the membrane-labilizing effects of lysolecithin. The data indicate that 3MI and indole can cause the release of marker lysosomal enzymes from LLC and that the effects of 3MI can be enhanced or decreased by the presence of some other lipotrophic agents.