The effect of inhibitors of protein and RNA synthesis on 1 alpha,25-dihydroxyvitamin D3-dependent calcium uptake in cultured embryonic chick duodenum
To determine whether 1 alpha, 25-dihydroxyvitamin D3-dependent increases in intestinal calcium uptake require de novo protein and RNA synthesis, the effects of several inhibitors of these processes have been re-examined in vitro using cultured embryonic chick duodenum. To minimize the contributions...
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Published in | The Journal of biological chemistry Vol. 256; no. 8; pp. 3848 - 3852 |
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Main Authors | , |
Format | Journal Article |
Language | English |
Published |
United States
American Society for Biochemistry and Molecular Biology
25.04.1981
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Subjects | |
Online Access | Get full text |
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Summary: | To determine whether 1 alpha, 25-dihydroxyvitamin D3-dependent increases in intestinal calcium uptake require de novo protein
and RNA synthesis, the effects of several inhibitors of these processes have been re-examined in vitro using cultured embryonic
chick duodenum. To minimize the contributions of antibiotic toxicity to the interpretation of results, care was taken to examine
inhibitor effects at early times after the onset of the 1 alpha, 25-dihydroxyvitamin D3 response. Cycloheximide at a concentration
of 5 microM blocked hormone-dependent calcium uptake at all times examined (6 to 24 h). Actinomycin D was similarly effective
at 6 to 12 h. The effects of cycloheximide were totally reversible while actinomycin D inhibition was only partially reversible.
These compounds inhibited protein or RNA synthesis by 68.4 +/- 1.4 and 51.4 +/- 1.1%, respectively. Anisomycin, another inhibitor
of polypeptide chain elongation and alpha-amanitin, an inhibitor of RNA polymerase I, also blocked 1 alpha, 25-dihydroxyvitamin
D3-dependent calcium uptake after 12 h in culture. These results further strengthen the hypothesis that 1 alpha, 25-dihydroxyvitamin
D3 stimulates intestinal calcium transport via a nuclear mechanism involving new gene expression. |
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ISSN: | 0021-9258 1083-351X |
DOI: | 10.1016/S0021-9258(19)69534-7 |