Immunohistochemical analysis of Na+/I- symporter distribution in human extra-thyroidal tissues.
131Iodine concentration has been described in several extra-thyroidal tissues. Recent evidence has shown that iodine uptake is achieved by the recently cloned human Na(+)/I(-) symporter (hNIS) gene. However, conflicting results were observed in the expression of hNIS transcripts in extra-thyroidal tissues. In order to document further the distribution of hNIS, we investigated its expression using an immunohistochemical method, based on a polyclonal antibody raised against a synthetic peptide. Various extra-thyroidal tissues were examined, particularly from the digestive tract. Our results confirm that the salivary glands and the stomach express hNIS protein significantly. In contrast, hNIS was undetectable in the colon but the rectal mucosa, which has never been examined, exhibited positive immunohistochemical staining. Other digestive tissues, including the oesophagus, small intestine and appendix, were negative. Weak staining was observed in the mammary gland, indicating that hNIS is expressed in this tissue. The pancreas, skin, ovaries, spleen and kidney showed no positive immunostaining.
Vayre
L
L
Departments of Medicine, Institut Gustave-Roussy, 94805 Villejuif, France.
Sabourin
J C
JC
Caillou
B
B
Ducreux
M
M
Schlumberger
M
M
Bidart
J M
JM
D002352:Carrier Proteins / Q000032:analysis*; D006801:Humans; D007150:Immunohistochemistry; D007455:Iodine; D007457:Iodine Radioisotopes; D008565:Membrane Proteins / Q000032:analysis*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D027981:Symporters; D013961:Thyroid Gland / Q000378:metabolism; D014018:Tissue Distribution; D000099209:Sodium-Iodide Symporters
D002352:Carrier Proteins; D007455:Iodine; D007457:Iodine Radioisotopes; D008565:Membrane Proteins; D027981:Symporters; D000099209:Sodium-Iodide Symporters