title: [Plasma levels of cortisol and opioid peptide beta-endorphin during spontaneous vaginal delivery].
abstract: BACKGROUND
  Labor pain is very frequent in clinical practice, but the underlying mechanisms as well as numerous neuroendocrine responses activated by such pain have not been fully explained yet.
  
  
  OBJECTIVE
  The objective of the study was to determine the influence of labor pain on plasma levels of cortisol and opioid peptide beta-endorphin.
  
  
  METHODS
  Cortisol and beta-endorphin levels were measured in blood plasma of: health, non-pregnant women (group 1, n=8), health pregnant women (group 2, n=8) and in parturitions, through fourth ages (group 3, n=8). Plasma level ofcortisol was measured by radioimmunoassay, and beta-endorphin by enzyme immunoassay. Data were expressed as mean +/- standard error of mean and were analyzed by Student's t test and Mann Whitney test.
  
  
  RESULTS
  Plasma level of cortisol in group 2 was significantly increased compared to the group 1. During labor progression, plasma level of cortisol was rising till the third labor age. Plasma level of cortisol in fourth labor age was not significantly different from the age one and group 1. Plasma level of beta-endorphin was (ng/L): in group 1: 64 +/- 20, group 2: 70 +/- 22, group 3: the first labor age: 75 +/- 15, the second labor age: 193 +/- 54, the third labor age: 346 +/- 97 and the fourth labor age: 114 +/- 31.
  
  
  CONCLUSIONS
  These results indicate that both beta-endorphin and cortisol are involved in regulation and modulation of labor pain and stress.
authors.forename: Ljubica
authors.initials: L
authors.lastname: Arsenijević
authors.forename: Zvezdana
authors.initials: Z
authors.lastname: Kojić
authors.forename: Nada
authors.initials: N
authors.lastname: Popović
mesh_terms: D000328:Adult; D005260:Female; D006801:Humans; D006854:Hydrocortisone / Q000097:blood*; D048949:Labor Pain / Q000097:blood*; D018377:Neurotransmitter Agents / Q000097:blood*; D011247:Pregnancy; D001615:beta-Endorphin / Q000097:blood*
chemical_list: D018377:Neurotransmitter Agents; D001615:beta-Endorphin; D006854:Hydrocortisone