Chondroitin sulfate proteoglycan phosphacan/RPTPbeta in the hypothalamic magnocellular nuclei.
The hypothalamo-neurohypophysial system synthesizes and releases arginine vasopressin (AVP) and oxytocin (OXT) with physiological stimulation. In the present study, we investigated localization of a chondroitin sulfate proteoglycan (CSPG), phosphacan/RPTPbeta, in the supraoptic nucleus (SON) and paraventricular nucleus (PVN) of adult rats at both the light and electron microscopic levels. Immunohistochemical analyses demonstrated stronger phosphacan/RPTPbeta immunoreactivity within the SON and PVN compared with adjacent hypothalamic areas. Double labeling experiments showed phosphacan/RPTPbeta immunoreactivity constituting punctate networks to surround the somata and dendrites of AVP- and OXT-secreting magnocellular neurons. Electron microscopic examination further revealed strong phosphacan/RPTPbeta immunoreactivity at extracellular membrane surface of some axons, somata, and dendrites of the SON, but not of synaptic junctions. Interestingly, phosphacan/RPTPbeta immunoreactivity was also observed at extracellular surface membrane between astrocytic processes and neurons rather than between magnocellular neurons. The present results indicate the high expression of the CSPG, phosphacan/RPTPbeta at the extracellular space in the hypothalamic AVP- and OXT-secreting magnocellular neurons.
Miyata
Seiji
S
Department of Applied Biology, Kyoto Institute of Technology, Matsugasaki, Sakyo-ku, Kyoto 606-8585, Japan. smiyata@ipc.kit.ac.jp
Shinga
Ichiro
I
Taguchi
Katsutoshi
K
Nakashima
Toshihiro
T
Kiyohara
Toshikazu
T
Oohira
Atsuhiko
A
D000818:Animals; D011508:Chondroitin Sulfate Proteoglycans / Q000032:analysis* / Q000276:immunology; D005110:Extracellular Space / Q000737:chemistry; D007150:Immunohistochemistry; D008297:Male; D018613:Microscopy, Confocal; D008854:Microscopy, Electron; D010286:Paraventricular Hypothalamic Nucleus / Q000737:chemistry* / Q000648:ultrastructure*; D051381:Rats; D054633:Receptor-Like Protein Tyrosine Phosphatases, Class 5; D013495:Supraoptic Nucleus / Q000737:chemistry* / Q000648:ultrastructure*
D011508:Chondroitin Sulfate Proteoglycans; C516897:Ptprz1 protein, rat; D054633:Receptor-Like Protein Tyrosine Phosphatases, Class 5