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Relationship Between Plasma and Cerebrospinal Fluid Norepinephrine and Dopamine Metabolites in a Nonhuman Primate
Author(s) -
Greene Karl A.,
Faull Kym F.
Publication year - 1989
Publication title -
journal of neurochemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.75
H-Index - 229
eISSN - 1471-4159
pISSN - 0022-3042
DOI - 10.1111/j.1471-4159.1989.tb07387.x
Subject(s) - homovanillic acid , normetanephrine , endocrinology , medicine , cerebrospinal fluid , dopamine , norepinephrine , chemistry , catecholamine , metabolite , biology , serotonin , receptor
Major and minor pathways of metabolism in the mammalian CNS result in the formation of 3‐methoxy‐4‐hydroxyphenylethylene glycol (MHPG) and normetane‐phrine (NMN) from norepinephrine (NE), and homovanillic acid (HVA) and 3‐methoxytyramine (3‐MT) from dopamine (DA), respectively. The correlational relationships between HVA and 3‐MT and between MHPG and NMN in primate CSF and plasma have not been described. These relationships may help to elucidate the usefulness of CSF and plasma metabolites as indices of CNS NE and DA activity. In addition, because NMN is unlikely to cross the blood‐brain barrier, CSF NMN concentrations would not be confounded by contributions from plasma, which is a major issue with CSF MHPG. We have obtained repeated samples of plasma and CSF from drug‐naive male squirrel monkeys and have measured the concentrations of MHPG, HVA, NMN, and 3‐MT to define their correlational relationships. For the NE me‐tabolites, significant correlations were obtained for CSF MHPG and NMN (r = 0.806, p < 0.001), plasma MHPG and CSF NMN ( r = 0.753, p < 0.001), and plasma and CSF MHPG ( r = 0.776, p < 0.001). These results suggest that CSF and plasma MHPG and CSF NMN may reflect gross changes in whole brain steady‐state noradrenergic metabolism. Only a single significant relationship was demonstrated for the DA metabolites, with CSF 3‐MT correlating with plasma HVA ( r = 0.301, p < 0.025). The results for the DA metabolites probably reflect regional differences in steady‐state brain dopaminergic metabolism.