Lysosomal enzymes and aging in vitro: subcellular enzyme distribution and effect of hydrocortisone on cell life-span.
The acid phosphatase and beta glucuronidase activities of four subcellular fractions (nuclear, mitochondrial-lysosomal, microsomal, supernatant) of WI-38 cells were compared during in vitro aging. All of the fractions showed an age-associated increase in activity. The increase in the lysosomal fraction was sufficient to account for the increase in the whole homogenate. The supernatant fraction showed a consistent and pronounced increase suggesting a decrease in latency. Hydrocortisone stabilized the lysosomes to some extent. However the presence of hydrocortisone (5 mug/ml) in the growth medium consistently extended the life-span of the culture 20-30%. The magnitude of the extension seemed to be directly proportional to the amount of time the cultures were exposed to the added hormone.
D000135:Acid Phosphatase / Q000378:metabolism*; D000367:Age Factors; D003585:Cell Biology; D002460:Cell Line; D002467:Cell Nucleus / Q000201:enzymology; D002470:Cell Survival; D002478:Cells, Cultured; D005966:Glucuronidase / Q000378:metabolism*; D006801:Humans; D006854:Hydrocortisone / Q000494:pharmacology*; D066298:In Vitro Techniques; D008247:Lysosomes / Q000201:enzymology*; D008861:Microsomes / Q000201:enzymology; D008928:Mitochondria / Q000201:enzymology; D013997:Time Factors
D000135:Acid Phosphatase; D005966:Glucuronidase; D006854:Hydrocortisone