A combination of radioimmunoassays and chromatography under
acid-dissociating conditions has been used to obtain profiles of
ACTH and LPH-related
peptides in human plasma and cerebrospinal fluid. The spectra of
peptides observed in these two fluids differ markedly.
ACTH,
beta-LPH,
gamma-LPH and
beta-endorphin are observed in the plasma of normal subjects and patients with increased pituitary
ACTH secretion, whereas cerebrospinal fluid contains
ACTH,
beta-LPH,
gamma-LPH and
beta-endorphin, a 31 000-molecular-weight putative precursor having
ACTH, LPH and
gamma-MSH immunoreactivities, as well as pro-gamma-MSH(1-77) and smaller immunoreactive
gamma-MSH fragments,
alpha-MSH was not observed in blood or cerebrospinal fluid but this pars intermedia
peptide and
corticotropin-like intermediate lobe peptide (
CLIP) were both found in tumour tissues obtained from patients with the
ectopic ACTH syndrome. In vitro studies of human pituitary tumour tissues confirmed concomitant secretion of
ACTH,
beta-LPH,
gamma-LPH,
beta-endorphin and
pro-gamma-MSH, which could be stimulated by a preparation of crude stalk median eminence and synthetic
arginine vasopressin, from the rat, and could be suppressed by
hydrocortisone. Clinical studies in which
electroacupuncture was used to alleviate the symptoms of
heroin withdrawal or recurrent
pain revealed that concentrations of
met-enkephalin and
beta-endorphin, respectively, may rise in cerebrospinal fluid in association with relief of symptoms.