UI - 000107

AU - Miller BE

AU - Lipman JJ

AU - Byrne WL

TI - Partial characterization of a novel endogenous opioid in human cerebrospinal fluid

AB - Human cerebrospinal fluid (CSF) contains many uncharacterized endogenous opioids, in addition to

the known enkephalins, endorphins, and dynorphins. These opioids may be separated by gel filtration

chromatography and identified by radioreceptor assay for opioid activity. One region of the chromatographic

elution profile, designated "Peak B" has previously been shown to be related to the pain status of chronic

pain patients. We now report that human Peak B isolated from the CSF of pain-free elective surgery patients

is present at a typical concentration equivalent in activity to 1.4 pmol of morphine sulfate per ml of CSF

measured by radioreceptor assay. At a dose of 0.06 and 0.12 pmol morphine sulfate equivalents of CSF

(MSE), injected into the cerebroventricular system of the mouse, Peak B produced an antinociceptive effect,

the intensity and duration of which was dose-dependent and which was antagonized by naloxone. The mouse

vas deferens (MVD) preparation was inhibited by Peak B in a manner that was sensitive to antagonism by

naloxone only at low (less than 1.0 microM) but not at higher (greater than 6.0 microM) concentrations of

the antagonist. Peak B activity in the MVD assay was unaffected by treatment with trypsin or alpha-

chymotrypsin

SO - Life Sciences 1987;41:2535-2545