Abstract

Electroacupuncture (EA) is used to treat chronic stress, however its mechanism(s) of action in allaying stress remain unclear. The interplay of stress hormones of the hypothalamus pituitary adrenal axis (HPA) and the sympathetic nervous System (SNS) is critical in the stress response. Our objective was to determine if EA at acupoint, stomach 36 (St36) is effective in preventing chronic cold stress-induced increase hormone levels in the rat by examining four groups of animals, three of which were exposed to cold and one was a non-treatment control group. Prior to exposure to the cold, two groups were treated with either EA at St36, or Sham EA, prior to 10 days of cold stress. The EASt36 animals demonstrated a significant decrease in peripheral HP hormones (ACTH, & CORT) compared to stress animals (p<0.05). These effects were specific; rats receiving Sham EA had elevation of these hormones, similar to the stress-only animals. These effects were mirrored centrally in the brain; corticotropin releasing hormone (CRH) levels were significantly (p<0.05) reduced in EASt36 animals compared to the other animals. Finally, EA effect on peripheral and adrenal SNS hormones (Norepinephrine [NE] and Neuropeptide Y-NPY, respectively) was examined, with no significant difference noted in adrenal TH or circulating NE in any of the groups. However, EA ST36 was effective in preventing stress-induced elevation is adrenal NPY mRNA. These results indicate EA at St36 blocks the chronic stress-induced elevations in the HPA axis and the sympathetic NPY pathway, which may be a mechanism for its specific stress-allaying effects.