title: Age-related differences in the induction of 2-5A synthetase and 2-5A dependent binding protein activities by interferon in guinea pig peritoneal macrophages.
abstract: 2-5A synthetase and binding protein activities in peritoneal macrophages have been compared between young (6 month) and old (22-24 month) guinea pigs. Enzyme activities are lower in aged animals with a 17% and a 31% reduction in synthetase and binding protein activities, respectively. In addition, the response to the addition of mouse fibroblast interferon by macrophages from these two age groups is also substantially different. Whereas addition of interferon to young guinea pig macrophages elicits a 3.8- and a 1.7-fold increase in the synthetase and binding protein activities, only a marginal elevation in these two enzyme activities is found with interferon-treated old guinea pig macrophages. Analysis by thin layer chromatography demonstrates a marked difference in the relative distribution of the various oligomeric forms of 2-5A synthesized by young or old guinea pig macrophages. The binding protein in old animals appears to be significantly more thermolabile than the corresponding activity from young animals. The altered response to interferon and the difference in enzymatic properties in aged animals may represent part of the mechanisms involved in the progressive loss of the adaptative ability of an organism to environmental changes during senescence.
mesh_terms: D015088:2',5'-Oligoadenylate Synthetase / Q000096:biosynthesis*; D000227:Adenine Nucleotides / Q000032:analysis; D000375:Aging; D000818:Animals; D002352:Carrier Proteins / Q000096:biosynthesis*; D004722:Endoribonucleases; D004790:Enzyme Induction; D006168:Guinea Pigs; D006358:Hot Temperature; D007372:Interferons / Q000494:pharmacology*; D008264:Macrophages / Q000378:metabolism*; D009843:Oligoribonucleotides / Q000032:analysis
chemical_list: D000227:Adenine Nucleotides; D002352:Carrier Proteins; D009843:Oligoribonucleotides; C023505:2',5'-oligoadenylate; D007372:Interferons; D015088:2',5'-Oligoadenylate Synthetase; D004722:Endoribonucleases; C031956:2-5A-dependent ribonuclease