Effects of stress and stress-therapy on plasma beta-endorphin-like immunoreactivity.

Beta-Endorphin-like immunoreactivity (B-ELI) was determined in the plasma of ten patients in presurgical stress conditions and after administration of dehydrobenzperidol (DHB, n = 3) and DHB plus fentanyl (Innovar, n = 7). Human B-ELI was determined by radioimmunoassay. The B-ELI was extracted from plasma with ODS-silica columns. B-ELI plasma levels increased significantly (P less than 0.02) during stress (7,7 +/- 1.2 fmol/ml and 23.3 +/- 4.1 fmol/ml for the control and stress, respectively). After administration of DHB plus fentanyl, a significant decrease (p less than 0.05) of B-ELI plasma levels was observed as compared with the presurgical stress conditions (10.1 +/- 0.8 fmol/ml and 21.1 +/- 5.2 fmol/ml, respectively), whereas no significant difference was observed (p greater than 0.05) in B-ELI plasma levels obtained in the DHB group compared with presurgical stress conditions (10.4 +/- 5.0 fmol/ml, and 28.3 +/- 7.1 fmol/ml, respectively). These results suggest a direct correlation between the emotional stressful situation of presurgery and increase in B-ELI plasma levels. The findings obtained with administration of DHB plus fentanyl seem to lend support to the hypothesis that this premedication is a good stress therapy.