Relation Between Plasma and Cerebrospinal Fluid Levels of 3-Methoxy-4-Hydroxyphenylglycol

Abstract

Concentrations of free 3-methoxy-4-hydroxyphenylglycol in the plasma and cerebrospinal fluid are highly correlated, but concentrations in the cerebrospinal fluid are always higher than those in plasma, even when large amounts of the catecholamine metabolite are derived from a tumor of the adrenal medulla. This is explained by considering the plasma and cerebrospinal fluid as a two-compartment system in which the rate constants for entry into and exit from the cerebrospinal fluid compartment are similar. 3-Methoxy-4-hydroxyphenylglycol that is synthesized, but not catabolized, in the central nervous system maintains cerebrospinal fluid levels at an increment over those in plasma. This increment can be used to provide the best available index of formation of 3-methoxy-4-hydroxyphenylglycol in the central nervous system.

Catecholamine Metabolism: A Contemporary View with Implications for Physiology and Medicine

“…Consequently, findings that amounts of free MHPG produced by the brain were 80% those excreted in urine led to the mistaken belief that the brain was the main source of urinary free MHPG (Maas et al, 1979). Later findings that most free MHPG is not excreted in urine, but is converted to VMA, led to a reevaluation of the contribution of the brain to urinary and plasma levels of MHPG (Kopin et al, 1983(Kopin et al, , 1984c. These analyses showed that the brain makes at most a 20% contribution to these levels.…”

“…These analyses showed that the brain makes at most a 20% contribution to these levels. Also, because MHPG diffuses freely from plasma into CSF, the close correlation between plasma and CSF levels of MHPG was shown to be expected (Kopin et al, 1983(Kopin et al, , 1984b. Thus, CSF MHPG levels cannot be interpreted as reflecting central norepinephrine metabolism unless corrected for MHPG levels in plasma.…”

Study on monoamine metabolite contents of cerebrospinal fluid in patients with neurodegenerative diseases.

“…2). Kopin et al (1982) reported a positive correlation between CSF-MHPG and the serum MHPG level. These might suggest the influences of peripheral catecholamine metabolism on the CSF-MHPG level.…”

On the significance of monoamines and their metabolites in the cerebrospinal fluid of the sheep.

“…from different sources might thus be a useful index of the biomedical status of adrenergic neurones. According to Kopin, Gordon, Jimerson & Polinsky (1983), concentrations of MHPG in the plasma and c.s.f. are highly correlated, but are always higher in the c.s.f.…”