ABSTRACT
To clarify the recovery patterns of spontaneous activity and liver damage after different stressors, female Fischer 344 rats were treated with <I>Propionibacterium aches</I> (<I>P, aches</I>) or water immersion stress before lipopolysaccharide (LPS) injection. They were then examined for wheel running activity, serum corticosterone concentration, serum alanine aminotransferase (ALT) activity, histological appearance of liver and plasma tumor necrosis factor alpha (TNF-a) concentration.<BR>The recovery in physical activity of <I>P. aches</I>-treated rats was faster than that of water immersion rats. One day after the stressors, serum corticosterone cancentration and ALT activity of <I>P. acnes</I>-treated rats were higher than that of water immersion rats. In addition, increases in serum ALT activity and plasma TNF- a, as well as massive necrosis of the liver in <I>P. acnes</I>-treated rats were observed seven days after stress treatment. The <I>P. acnes</I>-LPS rats also showed a reduction in survival rate after 24 hours. These results suggest that <I>P. acnes</I> stress causes serious inflammation when stimulated by LPS. Although rapid recovery in physical activity was not inhibited by <I>P. acnes</I> stress, it differed from the response of water immersion stress.
ABSTRACT
To clarify the recovery patterns of spontaneous activity and liver damage after different stressors, female Fischer 344 rats were treated with <I>Propionibacterium aches</I> (<I>P, aches</I>) or water immersion stress before lipopolysaccharide (LPS) injection. They were then examined for wheel running activity, serum corticosterone concentration, serum alanine aminotransferase (ALT) activity, histological appearance of liver and plasma tumor necrosis factor alpha (TNF-a) concentration.<BR>The recovery in physical activity of <I>P. aches</I>-treated rats was faster than that of water immersion rats. One day after the stressors, serum corticosterone cancentration and ALT activity of <I>P. acnes</I>-treated rats were higher than that of water immersion rats. In addition, increases in serum ALT activity and plasma TNF- a, as well as massive necrosis of the liver in <I>P. acnes</I>-treated rats were observed seven days after stress treatment. The <I>P. acnes</I>-LPS rats also showed a reduction in survival rate after 24 hours. These results suggest that <I>P. acnes</I> stress causes serious inflammation when stimulated by LPS. Although rapid recovery in physical activity was not inhibited by <I>P. acnes</I> stress, it differed from the response of water immersion stress.