Effects of chronic food restriction stress and chronic psychological stress on the development of adjuvant arthritis in male Long Evans rats
Abstrakt
The aim of the present experiments was to study the effect of stress of chronic food restriction (FR) and of repeated psychological challenge (PS) on the development of adjuvant arthritis in the Long Evans male rats. In the FR series, four groups of animals were compared: non-treated control (C) and arthritic (AA) rats, both with free access to food and water, and two analogous groups with a 40% food restriction-PR and AA-FR.
All animals were killed 22 days after injection of cFA. In the PS series, stress was induced by random daily exposures of the rats to isolation, over-crowding, food/water deprivation, foot shock, tilting, fear for 14 days before cFA injection and 12 days thereafter (groups: C, AA, PS, and AA-PS).
Arthritis causes swelling of the hindpaw, which was prevented in the AA-FR group. PS causes more severe disease symptoms: AA-PS rats had more severe hindpaw swelling than AA rats.
Forty percent food restriction associated with elevated CORT levels mitigated inflammatory parameters activated during AA. PS worsened the disease.
These results suggested that activated CORT is not the only cause of disease suppression, but some metabolic changes during FR play a role.