Cobalamin deficiency-induced down-regulation of p75-immunoreactive cell levels in rat central nervous system.
We investigated immunoreactivity for p75 neurotrophin receptor (NTR) in the spinal cord white matter and septum of rats made cobalamin-deficient (Cbl-D) by means of total gastrectomy or a Cbl-D diet. Cbl deficiency down-regulates p75NTR-immunoreactive cell levels in spinal cord white matter and septum with different time courses. On the whole, the spinal cord white matter seems to be more affected in terms of p75NTR-immunoreactive cells, most of which are astrocytes. The p75NTR-immunoreactive cell levels in the spinal cord white matter and septum normalized in rats treated with Cbl (scheme b) and killed 4 months after total gastrectomy. However, Western blot analysis of p75NTR in the spinal cords of Cbl-D rats shows increased p75NTR protein levels, which are resistant to Cbl replacement. These findings demonstrate that a neurotrophic vitamin (Cbl) positively regulates the levels of a neurotrophic receptor (p75NTR) (at least in terms of immunohistochemistry) in rat central nervous system, although the underlying mechanism(s) are still unknown.
Mutti
Elena
E
Institute of General Pathology, University of Milan, Via Mangiagalli 31, 20133 Milano, Italy.
Veber
Daniela
D
Stampachiacchiere
Barbara
B
Stampachiacchere
Barbara
B
Triaca
Viviana
V
Gammella
Elena
E
Tacchini
Lorenza
L
Aloe
Luigi
L
Scalabrino
Giuseppe
G
D000818:Animals; D002490:Central Nervous System / Q000378:metabolism* / Q000503:physiopathology; D015536:Down-Regulation / Q000502:physiology*; D005743:Gastrectomy / Q000009:adverse effects; D006710:Homocysteine / Q000097:blood; D007150:Immunohistochemistry; D008297:Male; D008764:Methylmalonic Acid / Q000097:blood; D009413:Nerve Fibers, Myelinated / Q000378:metabolism; D020932:Nerve Growth Factor / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D020800:Receptor, Nerve Growth Factor / Q000378:metabolism*; D020127:Recovery of Function / Q000187:drug effects / Q000502:physiology; D012686:Septal Nuclei / Q000378:metabolism / Q000503:physiopathology; D013116:Spinal Cord / Q000378:metabolism / Q000503:physiopathology; D014805:Vitamin B 12 / Q000378:metabolism* / Q000494:pharmacology; D014806:Vitamin B 12 Deficiency / Q000378:metabolism*
D020800:Receptor, Nerve Growth Factor; D006710:Homocysteine; D008764:Methylmalonic Acid; D020932:Nerve Growth Factor; D014805:Vitamin B 12