Influence of adrenal demedullation on stress induced alterations within the general adaptation behaviour of August-rats.
Based on new theoretical aspects of functional participation of adrenal glands in adaptation process, resulting from supplement of Selye's stress concept by integration of peptidergic systems, stress related adaptation behaviour of sham operated and demedullated August-rats, characterized by a high stress-sensitivity, were investigated. To characterize the stress related behaviour the following parameters were investigated: Number of rats surviving the exposure, alterations of body mass, occurrence of ulcers and hyperaemia in stomach, blood pressure behaviour, organ mass of adrenals, pituitaries and hypothalami in total, SPLIR in adrenals, pituitaries, hypothalami in total as well as in their special nuclei areas of N. ventromedialis and N. lateralis. The following conclusions can be drawn from experimental results: The important role of adrenal medulla in regulation of adaptive processes is given by the interaction between of its catecholamine system and its regulatory system of peptides (substance P, Opioids). Whereas demedullation itself makes visible alterations which are connected with the loss of adrenal-catecholamine system, additional stressor exposition makes visible alterations connected with the loss of adrenal-regulatory system. Investigations show differences in the sensitivity of reaction against the influence of stressors between catecholamine system (more sensitive) and regulatory system of adrenal medulla of August-rats. Demedullation has a different influence on alterations induced by mild manipulation stress (activation of catecholamine system) and by immobilization (activation of regulatory system). The influence of manipulation stress is inhibited and the influence of immobilization is increased by demedullation. Results of this investigations refer to the existence of feedback relations between the adrenal medulla and pituitary as well as between adrenal medulla and hypothalamus. Furthermore there are indications, that the adrenal medulla takes part in the regulation of extraadrenal sympathetic activity. The experimental data give furthermore a hint for the existence of a high stress sensitivity of August-rats primary caused by the CNS.(ABSTRACT TRUNCATED AT 250 WORDS)
Roske
I
I
Institute of Drug Research, Academy of Sciences, GDR, Berlin.
Umatov
E A
EA
Pevcova
E I
EI
Rathsack
R
R
Oehme
P
P
D000223:Adaptation, Psychological / Q000502:physiology*; D000313:Adrenal Medulla / Q000502:physiology*; D000818:Animals; D001794:Blood Pressure; D001835:Body Weight; D007033:Hypothalamus, Middle / Q000502:physiology; D007103:Immobilization; D010902:Pituitary Gland / Q000502:physiology; D051381:Rats; D013315:Stress, Psychological / Q000523:psychology*