Summary
The role of the pituitary-adrenocortical system (PACS) in body adaptation abilities
was studied on rats. The adaptation abilities were tested by a body working capacity
(the running time in a treadmill till fatigue). The single administration of ginseng
results in the increase of a working capacity up to 132%, the seven-day one up to
179%. This makes it possible to speak about two levels of adaptation, each being characterized
by a specific PACS status and a degree of PACS involvement in adaptation abilities.
The single administration of ginseng is accompanied by an increase in the basal level
of ACTH and corticosteroids. At a 7-day administration the basal level of ACTH and
corticosteroids does not change but PACS reactivity to the immobilising stress increases.
The preliminary administration of 15 mg/100 g b. w. hydrocortisone, 7 days before
testing of the working capacity and PACS status, causes the block in PACS function.
It results in the decrease of the basal corticosteroid content in plasma and the inability
of stress factor to cause the rise in the corticosteroid level. The PACS blocking
results in the decrease of a working capacity in normal rats not treated with ginseng
and in animals singly treated with ginseng. The PACS blocking effected the increment
in a working capacity caused by a 7-day ginseng administration to a lesser extent,
however, the decrease in a working capacity took place even in this case. The conclusion
is made that PACS status changes with the transition of a body to a higher level of
adaptation : PACS excitation occurs or the system excitability increases. PACS ensures
adaptation abilities in the norm as well as at higher levels of adaptation.
Key words
ACTH - Corticosterone - Working capacity - Adaptation - Ginseng - Stress
