الفهرس 
Introduction and Aim of the workOnly 14 pages are availabe for public view
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Abstract
the regulation of the HPA-axis exhibits three major characteristics: a circadian rhythm in basal activity, responsiveness of the system to stressors and feedback control of ACTH secretion by the steroid products of the adrenal cortex. The level of activity within the HPA-axis is determined by endogenous (circadian) and ,exogenous (stress) excitatory inputs, by inhibitory neural modulation and various stimulatory neurotransmitters and also by corticosteroid negative feedback. Chronic dministration of corticosteroids, results in suppression of the HPA-axis , which persists for avariable period before it restores its normal activity depending on the dose and duration of corticosteroid use. The data presented in the thesis can be summarized under the following headings: 1) SUPPRESSION, RECOVERY AND ENHANCEMENT OF THE RECOVERY OF THE HPA-AXIS AFTER CHRONIC PREDNISO(LO)NE ADMINISTRATION The suppression and recovery of the HPA-axis after chronic predniso (lo) ne administration was investigated in man and in the rat. The administration of 750 AM prednisolone (8.5 mg/rat/day via the drinking water) and 188 AM prednisolone (2 mg/rat/day) resulted in a deeper suppression of the HPA-axis than that produced by 94 AM prednisolone (1 mg/rat/day), as evidenced from the body and the adrenal weight loss, the adrenal response in vitro -, to different concentrations of ACTH the plasma.