title: Effect of intrathecal morphine during labor on maternal plasma beta-endorphin levels.
abstract: Plasma beta-endorphin was measured in 16 patients in labor prior to and after complete onset of analgesia with 1 mg of morphine administered intrathecally. Human beta-endorphin levels were determined by radioimmunoassay following silicic acid extraction of plasma samples and separation of the beta-endorphin fraction by gel chromatography. Plasma beta-endorphin levels decreased significantly (p less than 0.005) after intrathecal morphine from 76 +/- 9.7 to 46.3 +/- 9.1 fmol/ml (mean +/- SE), possibly because of decreased pituitary beta-endorphin secretion in response to alleviation of labor pain.
mesh_terms: D000328:Adult; D000698:Analgesia / Q000379:methods; D004723:Endorphins / Q000097:blood*; D005260:Female; D006801:Humans; D007278:Injections, Spinal; D007743:Labor, Obstetric; D009020:Morphine / Q000008:administration & dosage* / Q000627:therapeutic use; D011247:Pregnancy; D001615:beta-Endorphin
chemical_list: D004723:Endorphins; D001615:beta-Endorphin; D009020:Morphine