title: Inactivation kinetics of horseradish peroxidase microinjected into hepatocytes from mice of various ages.
abstract: We have studied degradation of proteins in liver parenchymal cells in culture obtained from mice of various ages. Horseradish peroxidase (HRP) was microinjected into the cells by the hypertonic-hypotonic method of Okada and Rechsteiner (Cell, 29 (1982) 33-41). Rate of inactivation of HRP was examined biochemically. Average functional half-lives of the enzyme were 50 h, 53 h and 75 h in the cells of young (3-8 months old), middle-aged (18-20 months old) and old (28-30 months old) mice, respectively. Thus, half-life of the inactivation of the enzyme in "old" cells was about 50% longer than that in "young" or "middle-aged" cells, suggesting that rate of protein degradation is lowered in senescent animals.
authors.affiliation: Department of Biochemistry, School of Pharmaceutical Science, Toho University, Chiba, Japan.
authors.forename: A
authors.initials: A
authors.lastname: Ishigami
authors.forename: S
authors.initials: S
authors.lastname: Goto
mesh_terms: D000375:Aging / Q000378:metabolism*; D000818:Animals; D006207:Half-Life; D006735:Horseradish Peroxidase / Q000378:metabolism*; D007700:Kinetics; D008099:Liver / Q000166:cytology / Q000378:metabolism*; D008297:Male; D051379:Mice; D008845:Microinjections; D010544:Peroxidases / Q000378:metabolism*
chemical_list: D006735:Horseradish Peroxidase; D010544:Peroxidases