Daw. Wolvers et al., TUMOR-NECROSIS-FACTOR-ALPHA - SPECIFIC BINDING-SITES IN RODENT BRAIN AND PITUITARY-GLAND, European cytokine network, 4(5), 1993, pp. 377-381
Specific binding sites for TNF-alpha in mouse and rat brain, spleen an
d pituitary gland have been visualized and characterized, using quanti
tative autoradiography. Mouse recombinant I-125-TNF-alpha has been use
d as a radioligand. In the spleen, TNF-alpha binding sites were highly
concentrated in the white pulpe of mouse and rat spleen. The IG(50),
as determined by displacement of radioligand by the unlabelled peptide
, was 0.3x10(-9)M for both species. In the mouse brain, a weak specifi
c binding was observed on the entire surface of the brain tissue. Howe
ver, none of the nervous or vascular structures were specifically labe
lled above this signal. No specific binding was detectable in the rat
brain tissue. In sharp contrast, in the anterior lobe of the pituitary
gland of both mouse and rat, high concentrations of specific binding
sites were detectable. Displacement curves in the mouse pituitary glan
d revealed the presence of two classes of binding sites with respectiv
e IC50 values of 10(-9) and 5x10(-11) M. A single class of TNF binding
site was demonstrated in the rat with an IC50 Of 10(-9)M. The presenc
e of TNF binding sites in the anterior pituitary gland underlines the
existence of regulatory pathways between the immune and neuroendocrine
system.