摘要:

The effects of previous chronic immobilization stress on the physiological responses of male rats to a novel chronic stressor (shock) were studied. Previous chronic exposure to immobilization reduced adrenocorticotropin (ACTH) and lactate responses to acute immobilization stress without altering the response to a novel acute stressor (tail shock). When subjected to chronic tail shock, body weight inhibition caused by chronic shock was greater in the rats not previously exposed to chronic immobilization, which suggests that there is cross-adaptation between different stressors. However, adrenocorticotropin adaptation to chronic shock was impaired by previous chronic immobilization. These data indicate that the existence of cross-adaptation to stressors might depend on the variable measured, the central nervous system pathways controlling the pituitary-adrenal axis being, apparently, resistant to cross-adaptation. This lack of cross-adaptation at certain levels can assure the maintenance of an adequate response to unknown environmental stimuli.

ISSN:0028-3835    

DOI:10.1159/000124921

出版商:S. Karger AG    

年代:1988

数据来源: Karger

摘要:

Infusion of 2 nmol atrial natriuretic factor (ANF) into the third cerebroventricle of conscious, orchidectomized male rats results in a significant inhibition of prolactin (PRL) secretion. This effect is prevented by prior treatment with the dopamine receptor antagonist, domperidone. Furthermore, domperidone reverses the inhibitory effect when given after ANF infusion. The PRL-inhibiting effect is absent as well following inhibition of tyrosine hydroxylase activity. These results suggest that ANF acts centrally at least in part via an interaction with endogenous dopaminergic systems and further suggests potent neuromodulatory actions of the peptide within the hypothalamus.

ISSN:0028-3835    

DOI:10.1159/000124922

出版商:S. Karger AG    

年代:1988

数据来源: Karger

ISSN:0028-3835    

DOI:10.1159/000124923

出版商:S. Karger AG    

年代:1988

数据来源: Karger