ISSN:
0003-276X
Keywords:
Life and Medical Sciences
;
Cell & Developmental Biology
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Medicine
Notes:
Light and electron microscopic radioautographs of the tissues of young rats which were sacrificed at various times after a single 3H-ribose injection revealed a wide distribution of the label.Nuclear reactions were seen over hepatocytes and other cell types. After removal of RNA by treatment with RNAse, most nuclear reactions were absent; they were, therefore, attributed to the incorporation of label into newly-synthesized RNA. In about 2% of the nuclei, however, labeling persisted after RNAse, but was absent after DNAse treatment, indicating uptake into newly-synthesized DNA. Hence, ribose may be taken up into nucleic acidsundergoing synthesis.In cells of liver and cartilage as well as in some muscle fibers, moderate reaction appeared over glycogen areas. Removal of the label by salivary amylase confirmed its uptake into glycogen.In mucous and other secretory cells, amylase resistant radioautographic reactions appeared over the Golgi region and later over secretion products. Presumably the label was incorporated into the glycoproteinmoieties of these secretions.Many, if not all, cells in the body appear to be able to utilize free exogenous ribose. It is presumed that ribose is first phosphorylated and then either incorporated into the RNA and DNA being synthesized in the nucleus or converted into the glucose or fructose derivatives used for glycogen and glycoprotein synthesis in the cytoplasm. That these pathways may play a significant physiological role is suggested by the recent finding of free ribose in the blood.
Additional Material:
12 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/ar.1091650409
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