ISSN:
1365-2826
Source:
Blackwell Publishing Journal Backfiles 1879-2005
Topics:
Medicine
Notes:
The aims of the present study were: 1) to compare the effect of two different chronic intermittent stressors i.e. cold-swimming versus ether, on the pituitary opioidergic system; 2) to evaluate the response of pituitary and plasma β-endorphin (βS-EP) to an acute stress in chronically stressed rats; and 3) to evaluate the effect of acetyl-l-carnitine treatment (10 mg/day/rat per os at night) on pituitary and plasma β-EP changes induced by two different types of chronic stress. The stressors were applied twice a day for 10 days. Rats were killed either before, during or after the last swimming or ether stress session. β-EP was measured by radioimmunoassay in anterior pituitary and in neurointermediate lobe extracts and in plasma. The following observations were made; 1) Chronic intermittent cold-swimming stress increased anterior pituitary contents and plasma β-EP levels; 2) both chronic intermittent cold-swimming stress and ether stress caused an increase of neurointermediate lobe β-EP contents; 3) as in control animals, rats exposed to chronic intermittent swimming stress reduced pituitary β-EP contents and raised plasma β-EP levels in response to the last acute swimming stress; 4) in contrast to control animals, rats exposed to chronic intermittent ether stress did not show any significant response of the pituitary-plasma opioidergic system to the last acute ether session; 5) the acetyl-l-carnitine treatment counteracted the changes evoked by chronic intermittent cold-swimming stress on the pituitary and plasma β-EP levels. The present data show that chronic intermittent ether stress impairs the capacity to respond to the acute stress and that acetyl-l-carnitine may modulate the changes of β-EP levels following chronic cold-swimming stress exposure.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1111/j.1365-2826.1993.tb00375.x
Permalink
