Vesicular inhibitory amino acid transporter is expressed in gamma-aminobutyric acid (GABA)-containing astrocytes in rat pineal glands.
Gamma-aminobutyric acid (GABA) is an inhibitory amino acid and acts as an intercellular transmitter in the central nervous system and peripheral tissues. In pineal glands, GABA is supposed to be a paracrine-like modulator of secretion of melatonin, although its mode of action, especially the sites of GABA signal appearance, is unknown. Vesicular inhibitory amino acid transporter (VIAAT) is a potential marker for the GABAergic phenotype. Here we presented evidence that VIAAT is expressed in GFAP-expressing astrocytes and a subpopulation of OX42-expressing microglia, but not in pinealocytes in cultured cells of rat pineal glands. The VIAAT-expressing cells also exhibit GABA immunoreactivity. Essentially the same results were obtained for pineal glands. These results suggest that GABA is stored and secreted from astrocytes and a subpopulation of microglia in pineal glands.
Department of Biochemistry, Faculty of Pharmaceutical Sciences, Okayama University, 1-1-1 Tshushima-naka, Okayama 700-8530, Japan.
Noriko
N
Echigo
Yoshinori
Y
Moriyama
D026905:Amino Acid Transport Systems / Q000235:genetics / Q000378:metabolism*; D000818:Animals; D000831:Animals, Newborn; D001253:Astrocytes / Q000378:metabolism*; D015152:Blotting, Northern / Q000379:methods; D015139:Blotting, Southern / Q000379:methods; D039481:CD11b Antigen / Q000378:metabolism; D018507:Gene Expression Regulation, Developmental / Q000502:physiology*; D005904:Glial Fibrillary Acidic Protein / Q000378:metabolism; D008297:Male; D009924:Organ Culture Techniques; D010870:Pineal Gland / Q000166:cytology*; D012333:RNA, Messenger / Q000096:biosynthesis; D051381:Rats; D017208:Rats, Wistar; D020133:Reverse Transcriptase Polymerase Chain Reaction / Q000379:methods; D016704:Synapsins / Q000378:metabolism; D016708:Synaptophysin / Q000378:metabolism; D050495:Vesicular Inhibitory Amino Acid Transport Proteins; D033921:Vesicular Transport Proteins / Q000235:genetics / Q000378:metabolism*; D005680:gamma-Aminobutyric Acid / Q000378:metabolism*
D026905:Amino Acid Transport Systems; D039481:CD11b Antigen; D005904:Glial Fibrillary Acidic Protein; D012333:RNA, Messenger; C118623:Slc32a1 protein, rat; D016704:Synapsins; D016708:Synaptophysin; D050495:Vesicular Inhibitory Amino Acid Transport Proteins; D033921:Vesicular Transport Proteins; D005680:gamma-Aminobutyric Acid