Immunoreactive β-Endorphin and Adrenocorticotropin in Human Cerebrospinal Fluid

Open Access
Publisher Website
Google Scholar
Abstract
To elucidate the significance of β-endorphin in human cerebrospinal fluid (CSF), CSF levels of β-endorphin-like immunoreactivity (β-EP-LI) in various diseases were determined by a specific radioimmunoassay and compared with simultaneously determined ACTH-like immunoreactivity (ACTH-LI) levels in CSF. CSF β-EP-LI and ACTH-LI in the control group, consisting of 5 normal subjects and 19 patients with nonendocrine diseases, were 22.2±1.3 and 14.6±0.4 fmol/ml, respectively. CSF levels of these peptides in patients with schizophrenia (n = 19) and acromegaly (n = 10) were not significantly different from those in the control group. Patients with Cushing's disease (n = 7) had significantly lower CSF β-EP-LI and ACTH-LI levels than those in the control group. Four of them showed a parallel increase in CSF β-EP-LI and CSF ACTH-LI levels after the complete removal of pituitary microadenomas (P < 0.05). Gel chromatography of CSF β-EP-LI from a normal volunteer, a control patient, and one patient each with catatonia, Nelson's syndrome, Cushing's syndrome (adrenal adenoma), and acromegaly gave similar patterns consisting of three peaks with the elution positions comparable to those of authentic β-endorphin, β-lipotropin, and possibly their precursor molecule. Gel chromatographic patterns of CSF β-EP-LI and ACTH-LI were compared in a normal volunteer. The first peaks of β-EP-LI and ACTH-LI eluted at the same position and the second peak of ACTH-LI coincided with the elution position of authentic ACTH. CSF β-EP-LI and ACTH-LI levels determined every 5 min over a period of 80 min in three normal volunteers did not show moment-to-moment variability. A significant correlation (r = 0.75, P < 0.001) was seen between CSF β-EP-LI and ACTH-LI levels in normal subjects and patients studied (n = 73). This suggests that β-endorphin and ACTH in human CSF share the common regulatory mechanism in normal and pathologic conditions.