Distribution of retinol-binding protein in the human digestive tract.

By employing polyclonal antibodies for retinol-binding protein (RBP), its distribution in the human pancreas and digestive tract mucosa was compared with those of transthyretin (TTR) and various peptide hormones. The materials used included surgically removed pancreas, esophagus, stomach, small and large intestines. Paraffin sections were stained by the indirect immunoenzyme method. The results indicate that RBP-containing cells are found in the pancreas and the gastrointestinal mucosa, but most frequently in the gastric antrum and duodenum. In the pancreas, RBP-containing cells are found in the islets and among acinar and ductal epithelial cells, and consistently stain for chromogranin A. RBP-containing cells in the gastrointestinal mucosa showed typical features of endocrine cells and also stained for chromogranin A. The distribution of TTR in these tissue sites resembled that of RBP, but the immunoreactive intensities of both peptides altered independently. Comparison of the distribution of RBP, TTR, and various gastrointestinal peptide hormones revealed that the distribution of RBP coincided with none of the other peptides, although some of the RBP-containing cells stained for most of the peptides examined and vice versa. These results suggest that RBP may be a consistent component of gastrointestinal endocrine cells.     

Influence of selenium deficiency on the acute cardiotoxicity of adriamycin in rats

The influence of selenium (Se) deficiency on the acute cardiotoxicity induced by the anticancer drug adriamycin (ADR) has been studied in rats by electrocardiography. Two categories were formed by feeding groups of rats a Se-supplemented and a Se-deficient diet. The supplemented animals were taken as normals. The two categories were treated with iv injections of saline solution containing ADR at doses of 0, 7.5, and 15 mg/kg body wt. The cardiac Se concentration and glutathione peroxidase (GSH-Px) activity in the Se-deficient groups were <2% lower than in the normals. The normal groups showed significant widening of the SaT and QaT durations when given 15 mg/kg ADR. The Se-deficient groups exhibited a dose-dependent widening of the SaT and QaT duration at 7.5 and 15 mg/kg and narrowing of the PQ duration at 15 mg/kg ADR. No heart rate or QRS duration changes were detected in both categories. Our results suggest that an imbalance of the antioxidant system is associated with Se deficiency and that Se plays a role in preventing the cardiac functional disorder attributable to oxygen free radical formation induced by ADR.     

Carbohydrate structures of a normal counterpart of the carcinoembryonic antigen produced by colon epithelial cells of normal adults

Normal Faecal antigen-2 (NFA-2) and non-specific crossreactingantigen-2 (NCA-2), cross-reacting with anticarcinoembryonicantigen (CEA) antibodies, were found in normal human faececand meconium, respectively. Because NFA-2, NCA-2 and CEA areconsidered as the same gene products, NFA-2 and NCA-2 shouldbe normal counterparts of CEA produced by colon epithelial cellsof normal adults and fetuses, respectively. Comparison of sugarchain structures of these three antigens is indispensable inorder to unravel the stnaural alteration induced by malignanttransformation and development of colon epithelial cells. Thesugar chain structures of CEA (Yamashita,K. et al., Cancer Res.,47,3451–3459,1987) and NCA-2 (Yarnashita,K. et al., J.Bid Chem, 264,17873-17881,1989) were previously reported. Inthis paper, the structures of the oligosaccharides releasedfrom four NFA-2 samples by hydrazinolysis were studied by meansof lectin-affinity column chromatography, endo- and em-glycosidasedigestion, methylation analysis, hydrazinolys-nitrous acid deaminationand electrospray ionization mass spectrometry. NFA-2 contains24–27 mol of N-linked sugar chains/molecule, which issimilar to NCA-2 (27 mol) and CEA (24–27 mol). In contrastto CEA, which contains {small tilde} 8% high-mannose-type sugarchains all sugar chains of NFA-2 are mono- to tetra-antennarycomplex-type chains having four types of tri-mannosyl cores,with or without bisecting N-acetylglucosamine and fucose residues.The structures of their outer chain moieties comprise Galß1