title: ACTH, beta-endorphin and met-enkephalin: peripheral modifications during the stress of human labor.
abstract: We investigated the psychoneuroendocrine and emotional correlates of the natural stress situation of human labor. State anxiety, subjective pain, plasma ACTH, peripheral plasma beta-lipotropin (Beta-LPH), beta-endorphin (Beta-EP), and met-enkephalin (Met-Enk) were serially evaluated at six predetermined time points before, and after labor in a sample of 14 women with normal pregnancies. State anxiety and subjective pain showed a progressive increase during labor, with a levelling during the final stage. Plasma Beta-EP and ACTH showed a similar progressive increasing from baseline until the end of labor. Beta-LPH showed no significant modification. Met-Enk remained at nearly baseline values throughout labor, with a marked progressive rise in the postpartum stage. The findings of this study seem to confirm the role of plasma Beta-EP as a stress hormone. Possible relationship between pain and anxiety curves and plasma Beta-EP are discussed in light of psychobiological studies on stress, the opioid system and analgesia. Plasma Met-Enk, according to our findings, should probably not be regarded as a stress hormone. Its rise in the postpartum stage might be as one of the psychoneuroendocrine mechanisms maintaining elevated prolactin levels during lactation.
mesh_terms: D000324:Adrenocorticotropic Hormone / Q000097:blood*; D000328:Adult; D001007:Anxiety / Q000097:blood; D004723:Endorphins / Q000097:blood*; D004744:Enkephalin, Methionine / Q000097:blood; D005260:Female; D006801:Humans; D007743:Labor, Obstetric; D010146:Pain / Q000097:blood; D011247:Pregnancy; D013312:Stress, Physiological / Q000097:blood*; D001615:beta-Endorphin; D008083:beta-Lipotropin / Q000097:blood
chemical_list: D004723:Endorphins; D004744:Enkephalin, Methionine; D001615:beta-Endorphin; D000324:Adrenocorticotropic Hormone; D008083:beta-Lipotropin