Immunocytochemical localization of rat intestinal 15 kDa protein, a member of cytoplasmic fatty acid-binding proteins.
Rat intestinal 15 kDa protein (I-15P) is a member of the family of cytoplasmic fatty acid-binding proteins. Using a specific antiserum against I-15P, we studied the tissue distribution and subcellular localization of this protein in the entire rat body. By immunoblot analysis of cytosolic proteins, I-15P was detected not only in the distal portion of small intestine but also in the ovary and adrenal gland. Immunohistochemically, I-15P was localized to the absorptive epithelial cells as well as a subpopulation of enterochromaffin cells in the intestine, the lutein cells in the ovary, and subpopulations of cortical cells in the adrenal gland. Furthermore, I-15P-like immunoreactivity was also demonstrated in the surface mucous cells of stomach and the granular convoluted tubule cells of submandibular gland. Immuno-electron microscopy showed that the immunoreactivity was confined to the cytoplasmic matrix region, except in the enterochromaffin cells and granular convoluted tubule cells, where it was localized in the secretory granules. The present findings suggest that I-15P plays a role in the cellular metabolism of steroids.
Amano
O
O
Department of Anatomy, School of Medicine, Kanazawa University, Japan.
Kanda
T
T
Ono
T
T
Iseki
S
S
D000311:Adrenal Glands / Q000378:metabolism; D000818:Animals; D002352:Carrier Proteins / Q000737:chemistry / Q000378:metabolism*; D003593:Cytoplasm / Q000378:metabolism*; D000071438:Fatty Acid-Binding Protein 7; D050556:Fatty Acid-Binding Proteins; D005260:Female; D015151:Immunoblotting; D007150:Immunohistochemistry; D007413:Intestinal Mucosa / Q000378:metabolism*; D008297:Male; D008970:Molecular Weight; D009363:Neoplasm Proteins; D009419:Nerve Tissue Proteins; D010053:Ovary / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D013363:Submandibular Gland / Q000378:metabolism; D014018:Tissue Distribution
D002352:Carrier Proteins; C490174:Fabp7 protein, rat; D000071438:Fatty Acid-Binding Protein 7; D050556:Fatty Acid-Binding Proteins; D009363:Neoplasm Proteins; D009419:Nerve Tissue Proteins