title: Is polyamine decrease a common feature of apoptosis? Evidence from gamma rays- and heat shock-induced cell death.
abstract: Here we report that in rat thymocytes undergoing apoptosis upon two different stimuli, such as heat shock treatment and gamma irradiation, an early mRNA accumulation of ornithine decarboxylase (ODC)--the rate-limiting enzyme of polyamine biosynthesis--was followed by a very marked increase in ODC activity (28-40 and 6-8-fold, respectively). However, polyamine levels started to decrease before the appearance of DNA laddering, being putrescine and spermidine strongly diminished (8-12 hs), and spermine even depleted (12 hs). Taken together with our previous data on another model of apoptosis, i.e., glucocorticoid-induced cell death (Desiderio et al., Cell Growth Differ. 6: 505-513, 1995), these results suggest that an imbalance of polyamine metabolism, i.e., a strong activation of ODC and a paradoxical decrease of the intracellular polyamine content, might be a general feature of the apoptotic process.
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D017209:Apoptosis / Q000528:radiation effects; D016923:Cell Death / Q000187:drug effects*; D002478:Cells, Cultured; D002851:Chromatography, High Pressure Liquid; D004247:DNA / Q000302:isolation & purification / Q000528:radiation effects; D004587:Electrophoresis, Agar Gel; D005720:Gamma Rays; D006358:Hot Temperature; D007700:Kinetics; D009955:Ornithine Decarboxylase / Q000378:metabolism; D011073:Polyamines / Q000378:metabolism*; D011700:Putrescine / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D013095:Spermidine / Q000378:metabolism; D013096:Spermine / Q000378:metabolism; D013950:Thymus Gland / Q000166:cytology / Q000473:pathology / Q000528:radiation effects*; D013997:Time Factors
chemical_list: D011073:Polyamines; D013096:Spermine; D004247:DNA; D009955:Ornithine Decarboxylase; D013095:Spermidine; D011700:Putrescine