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Blood‐borne interleukin‐1 alpha is transported across the endothelial blood‐spinal cord barrier of mice.
Author(s) -
Banks W A,
Kastin A J,
Ehrensing C A
Publication year - 1994
Publication title -
the journal of physiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.802
H-Index - 240
eISSN - 1469-7793
pISSN - 0022-3751
DOI - 10.1113/jphysiol.1994.sp020293
Subject(s) - spinal cord , blood–brain barrier , cerebrospinal fluid , central nervous system , interstitial space , parenchyma , interstitial fluid , medicine , perivascular space , ependymal cell , fluid compartments , pathology , chemistry , anatomy , neuroscience , biology , endocrinology , extracellular fluid , extracellular , biochemistry
1. Previous work has shown that one mechanism by which blood‐borne interleukin‐1 alpha (IL‐1) may be able to affect the central nervous system (CNS) is by direct transport into the brain across the blood‐brain barrier (BBB). The BBB of the brain consists of endothelial (between blood and interstitial fluid) and ependymal (between blood and cerebrospinal fluid) barriers. Which of these barriers IL‐1 can cross has not previously been investigated. At the spinal cord, which could be the site of action for some of the effects of IL‐1 such as analgesia, the BBB consists only of the endothelial barrier. 2. We show here that IL‐1 labelled with 125I (I‐IL) is transported across the BBB of the spinal cord by a saturable system similar to the one previously described for the brain. High performance liquid chromatography (HPLC) showed that most of the material entering the spinal cord represented intact I‐IL. The BBB of the spinal cord was no more leaky to radioactively labelled albumin than the BBB of the brain and was not disrupted by 50 micrograms kg‐1 of IL‐1. 3. Capillary depletion showed that most of the I‐IL entered the parenchymal‐interstitial fluid space of the spinal cord with only a modest amount being sequestered by the endothelial cells of its BBB. 4. I‐IL entered the cervical, thoracic and lumbar regions of the spinal cord equally well. I‐IL entering at the brain and diffusing caudally was estimated only to account for about 1% of the total radioactivity found in the spinal cord after i.v. injection.(ABSTRACT TRUNCATED AT 250 WORDS)