| Autor: |
Trown PW, Palleroni AV, Bohoslawec O, Richelo BN, Halpern JM, Gizzi N, Geiger R, Lewinski C, Machlin LJ, Jetten A, Jetten ME |
| Jazyk: |
angličtina |
| Zdroj: |
Cancer research [Cancer Res] 1980 Feb; Vol. 40 (2), pp. 212-20. |
| Abstrakt: |
A new rapid assay has been developed for measurement of the binding of [3H]retinoic acid to cellular retinoic acid-binding protein. The assay, which uses activated charcoal for the separation of bound from unbound retinoic acid, was used to determine the concentration required to inhibit the binding of [3H]retinoic acid to cellular retinoic acid-binding protein by 50% for 18 retinoids with free carboxylic acid groups. Partially purified cellular retinoic acid-binding proteins isolated from rat testes and carcinogen-induced rat mammary tumors were used for these determinations. The following parameters were also determined for some or all of the retinoids: hypervitaminosis A doses; activity against carcinogen-induced mouse skin papillomas; inhibition of growth of a rat chondrosarcoma; inhibition of growth of 3T6 cells; and differentiation of the embryonal carcinoma cell line PCC4.azaIR. While all retinoids that are potent in these biological test systems bind tightly to cellular retinoic acid-binding protein, the converse is not true. The lack of a consistent quantitative correlation between 50% inhibitory concentration and biological activity is probably due to insufficient concentrations of the retinoid in the target tissue or celll, which is a consequence of factors such as absorbability, metabolism, tissue distribution, and pharmacokinetics. |
| Databáze: |
MEDLINE |
| Externí odkaz: |
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