Accumulation of circulating endogenous and exogenous immunoglobulins by hypothalamic magnocellular neurons.
Rat monoclonal antibodies, used in immunocytochemistry of normal rat brain, result in a granular reaction product within neurons innervating areas lacking a blood-brain barrier. Immunocytochemical characterization shows that the staining is independent of the primary antibody and exclusively dependent on the presence of anti-rat immunoglobulin. This granular staining could be selectively eliminated by pre-adsorption of the anti-rat immunoglobulin with purified rat immunoglobulin or disruption of microtubule retrograde transport systems by intraventricular injection of colchicine. A dependence on retrograde transport and complete independence from local synthesis was further substantiated by the rapid uptake and accumulation of intravenously administered rabbit or rat [125I]immunoglobulins by the supraoptic-neurohypophysial system. Immunoelectron microscopy was used to identify the endogenous rat immunoglobulin within lysosome-like organelles in the cytoplasm of magnocellular neuroendocrine cells. The uptake and incorporation of plasma macromolecules into the lysosomal system of magnocellular and other neurons projecting to regions with a weak blood-brain barrier may represent a novel mode of blood-central nervous system interactions.
Meeker
M L
ML
Department of Neurology, University of North Carolina School of Medicine, Chapel Hill 27514.
Meeker
R B
RB
Hayward
J N
JN
D000818:Animals; D000911:Antibodies, Monoclonal; D002795:Choline O-Acetyltransferase / Q000276:immunology* / Q000378:metabolism; D007031:Hypothalamus / Q000166:cytology / Q000276:immunology*; D007074:Immunoglobulin G / Q000378:metabolism*; D008297:Male; D009474:Neurons / Q000166:cytology / Q000276:immunology*; D009928:Organ Specificity; D010902:Pituitary Gland / Q000166:cytology / Q000276:immunology; D051381:Rats; D011919:Rats, Inbred Strains; D013495:Supraoptic Nucleus / Q000276:immunology
D000911:Antibodies, Monoclonal; D007074:Immunoglobulin G; D002795:Choline O-Acetyltransferase