Accumulation of 14C-5,6-dihydroxytryptamine-melanin in intrathecal and subependymal phagocytes of the rat CNS and possible routes of their elimination from brain

Journal Article · Thu Jan 01 04:00:00 EST 1981 · Prog. Clin. Biol. Res.; (United States)

OSTI ID:5504441

Baumgarten, H G; Moritz, F; Schlossberger, H G

14C-5,6-DHT-Melanin, a labelled synthetic polymer resembling the naturally occurring melanin formed in brain by autoxidation of dopamine, was injected into the left lateral ventricle of adult rats, and its fate followed by autoradiography and by transmission electron microscopy of structures identified as labelled in preceding light micrographs, and by EM-autoradiography. Shortly after injection, melanin particles (easily identified in the em because of their size, structure and electron opacity) were seen ingested by supraependymal and epiplexus cells, by cells residing in the piaarachnoid, i.e. free subarachnoidal cells and perivascular cells, and by subependymally located microglia-like cells with intraventricular processes. Up to day four, an increase in the number of labelled phagocytes in the CSF was noted which transformed into typical reactive macrophages. Beyond this time, many intraventricular melanin-loaded phagocytes formed rounded clusters; cells of such clusters were subsequently found to invade the brain parenchyma by penetrating the ependymal lining and to accumulate in the perivascular space of brain vessels. 14C-Melanin-storing macrophages were found in the marginal sinus of the deep jugular lymph nodes suggesting emigration of CNS-derived phagocytes via lymphatics or prelymphatics that contact the subarachnoidal space compartment. This does not exclude the possibility that some of the macrophages leave the brain via the systemic circulation by penetrating the vascular endothelium; these may be disposed of in peripheral organs other than the lymph nodes.

• Research Organization: Department of Neuroanatomy and Electron Microscopy, Free University of Berlin, GFR
• OSTI ID: 5504441
• Journal Information: Prog. Clin. Biol. Res.; (United States), Journal Name: Prog. Clin. Biol. Res.; (United States) Vol. 59A; ISSN PCBRD
• Country of Publication: United States
• Language: English

Related Subjects

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551001 -- Physiological Systems-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
ANIMAL CELLS
ANIMALS
AUTORADIOGRAPHY
BODY
BRAIN
CARBON 14 COMPOUNDS
CENTRAL NERVOUS SYSTEM
DISTRIBUTION
ELECTRON MICROSCOPY
HYDROXY COMPOUNDS
ISOTOPE APPLICATIONS
LABELLED COMPOUNDS
MAMMALS
MELANIN
METABOLISM
MICROSCOPY
NERVOUS SYSTEM
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
ORGANS
PHAGOCYTES
PIGMENTS
RATS
RODENTS
SOMATIC CELLS
TISSUE DISTRIBUTION
TRACER TECHNIQUES
TRANSMISSION ELECTRON MICROSCOPY
VERTEBRATES