Plasma and cellular retinoid-binding proteins and transthyretin (prealbumin) are all localized in the islets of Langerhans in the rat.
AUTOR(ES)
Kato, M
RESUMO
The immunohistochemical localization of plasma retinol-binding protein (RBP), cellular retinol-binding protein (CRBP), and transthyretin (TTR) was studied in rat pancreas. The studies employed antibodies purified by immunosorbent affinity chromatography, permitting the specific staining and localization of each antigen by the unlabeled peroxidase-antiperoxidase method. Specific immunostaining for each of these three proteins was found localized to the islets of Langerhans. Both RBP and CRBP were localized in cells that were peripherally distributed within the islets, with an anatomic distribution that resembled that of the glucagon-containing A cells. Immunoreactive TTR was localized in cells that were more centrally distributed in the islets, with an anatomic distribution that resembled that of the insulin-containing B cells. These findings were confirmed by radioimmunoassay of a homogenate of isolated rat islets. By using sensitive and specific radioimmunoassays for each antigen, unusually high levels of CRBP, RBP, TTR, and cellular retinoic acid-binding protein (CRABP) were found in rat islets. The physiological significance of the localization of RBP, CRBP, CRABP, and TTR in the islets is not known. The findings suggest that retinoids and their binding proteins may play important metabolic roles within islet cells, and hence that they may be involved in some way in the biological, endocrine, function of the islets.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=397584Documentos Relacionados
- Interphotoreceptor retinoid-binding protein promotes rhodopsin regeneration in toad photoreceptors.
- Cloning and nucleotide sequencing of transthyretin (prealbumin) cDNA from rat choroid plexus and liver.
- Cloning and nucleotide sequencing of transthyretin (prealbumin) cDNA from rat choroid plexus and liver
- Hypomethylation of the interphotoreceptor retinoid-binding protein (IRBP) promotor and first exon is linked to expression of the gene.
- Cardiac amyloidosis: a review and report of a new transthyretin (prealbumin) variant.