The polyamine stress response: tissue-, endocrine-, and developmental-dependent regulation11Abbreviations: PA, polyamine; PSR, polyamine stress response; HPA, hypothalamic–pituitary–adrenocortical; ODC, ornithine decarboxylase.

摘要: Transient alterations in polyamine (PA) metabolism, termed the stress response (PSR), constitute a common cellular to stressful stimuli. In contrast adult brain and liver, PSR adrenal gland thymus is characterized by reduction PA metabolism. The undergoes an early postnatal period of non-responsiveness. aim present study was twofold: i) determine whether thymus, developmentally regulated as that ii) establish neuronal hormonal signals can activate independently. Ornithine decarboxylase (ODC) activity tissue concentrations served markers PSR. Changes were measured male Wistar rats during development at 2 weeks after adrenalectomy adults. Unlike brain, direction peripheral organs did not undergo developmental changes. After adrenalectomy, activated liver acute (2-hr) restraint stress, but characteristic induced hippocampus. However, dexamethasone injection (3 mg/kg) induce all adrenalectomized rats. results justify following conclusions: organs, regulated; switch mature corresponds time cessation "stress hypo-responsive period" hypothalamic-pituitary-adrenocortical (HPA) axis; iii) periphery, appears be dependent principally on stress-induced activation HPA axis increased circulating glucocorticoid rather than activation; iv) however, independently glucocorticoids or direct circuitry; v) up-regulation PSR, constructive may implicated cell survival, while its down-regulation, death.