title: Intracellular accumulation of a fluorescent derivative of paromomycin in human fibroblasts.
abstract: Human fetal lung fibroblasts grown in the presence of dansyl-paromomycin (DNS-Pm), a fluorescent derivative of the aminoglycoside antibiotic, paromomycin, probably accumulate DNS-Pm in the lysosomes. The intracellular concentration of DNS-Pm is proportional to the extracellular concentration and to the length of time cells are exposed to the compound. The accumulation of DNS-Pm by human fibroblasts continued to increase for several days, reaching a saturation after 7 days. The kinetic data are consistent with the establishment of a steady state in the cell between fluid-phase pinocytosis and exocytosis of DNS-Pm. About 80% of the intracellular DNS-Pm ws released in 24 hr when fresh medium without the analogue was added. The residual 20% remained within the cells, suggesting that it may be irreversibly bound to the lysosomes, endoplasmic reticulum, or ribosomes. The uptake of paromomycin by cells in culture may be a useful means to study error propagation during growth and lifespan of cells in vitro.
mesh_terms: D055598:Chemical Phenomena; D002621:Chemistry; D003619:Dansyl Compounds / Q000378:metabolism; D004705:Endocytosis; D005089:Exocytosis; D005260:Female; D005347:Fibroblasts / Q000378:metabolism; D006801:Humans; D008168:Lung / Q000378:metabolism*; D009682:Magnetic Resonance Spectroscopy; D008856:Microscopy, Fluorescence; D010303:Paromomycin / Q000031:analogs & derivatives / Q000378:metabolism*; D011247:Pregnancy; D013056:Spectrophotometry, Ultraviolet; D013997:Time Factors
chemical_list: D003619:Dansyl Compounds; D010303:Paromomycin; C037223:dansylparomomycin