beta-endorphin and Testicular-Neoplasms

It has been hypothesized that the endogenous opioid (endorphin) system is related to biologic stress responses. We have used general surgery as a naturalistic model for studying stress response in humans. Abdominal surgery, but not anesthesia induction, was associated with significant increases in plasma beta-endorphin immunoreactivity and cortisol. Both hormones decreased significantly during post-operative morphine administration. Baseline and mean surgery levels of plasma beta-endorphin immunoreactivity showed an inverse relationship with post-operative analgesic requirement. These data support involvement of the endorphin system in human stress response and in human endogenous analgesic mechanisms. Findings also support the concept that baseline or psychologically stimulated levels of arousal may also be an important determinant in the physiology of stress response and pain perception.

Topics: Adolescent; Adult; beta-Endorphin; Endorphins; Female; Humans; Hydrocortisone; Male; Middle Aged; Morphine; Ovarian Neoplasms; Pain, Postoperative; Radioimmunoassay; Stress, Physiological; Testicular Neoplasms

The relationship between stress and human behavior is studied using general surgery as a stress paradigm. As indices of arousal, presurgery and surgery plasma beta-endorphin and cortisol immunoreactivity are assessed. Behavioral analysis is restricted to the measurement of total morphine usage during the first 24 postoperative hours under standard PRN (as needed) clinical orders. Individual patient morphine requirements vary widely (12-56 mg). Both presurgery and mean surgery plasma beta-endorphin levels significantly predict morphine requirement, and similar, although not so strong, correlations are found for cortisol. Patient age is also found to be negatively correlated with morphine requirement. When multiple regression analysis is used, the variables of plasma beta-endorphin and age predict 70% of the variance in individual morphine requirements.

Topics: Adolescent; Adult; Arousal; beta-Endorphin; Endorphins; Female; Humans; Hydrocortisone; Male; Middle Aged; Morphine; Ovarian Neoplasms; Pain, Postoperative; Stress, Physiological; Testicular Neoplasms

The role of the endogenous opioid system in humans was studied using three clinical research strategies. High doses of the opiate antagonist naloxone (up to 4 mg/kg) were administered to normal volunteers. Dose-dependent increases in self-ratings of tension-anxiety and anger-hostility were observed, supporting the hypothesized involvement of the endogenous opioid system in the modulation of human mood and feelings of well-being. Accompanying dose-dependent increases in systolic blood pressure and respiratory rate were found, suggesting that the lower doses of naloxone utilized in previous clinical studies were not sufficient to block the endogenous opioid system. CSF opioid activity in psychiatric patients and normals was measured using a sensitive radioreceptor assay developed by the authors. Results suggest diminished endogenous opioid system activity in some schizophrenics, and a relationship between opioid activity and state change in manic-depressive illness and anorexia nervosa. A complex but consistently observed relationship between ratings of anxiety and CSF opioid activity in normals and patients is consistent with basic science and clinical data suggesting interactions between CNS noradrenergic and opioid systems. General surgery was used as a strategy for studying the relationship of the endogenous opioid system to stress in humans; robust increases in levels of plasma beta-endorphin immunoreactivity accompanying surgical stress and an inverse relationship between patient levels of plasma beta-endorphin immunoreactivity and postoperative analgesic requirement were observed. These data support the involvement of the endogenous opioid system in the human stress response and suggest that hormonal stress response and endogenous opioid system activity may relate to human endogenous analgesic mechanisms.

Topics: Adolescent; Adult; Affect; beta-Endorphin; Blood Pressure; Dose-Response Relationship, Drug; Endorphins; Female; Heart Rate; Humans; Male; Mental Disorders; Middle Aged; Naloxone; Ovarian Neoplasms; Psychiatric Status Rating Scales; Receptors, Opioid; Research; Respiration; Stress, Physiological; Testicular Neoplasms