Abstract
Mouse fibroblasts growing in vitro (L cells) contain a binding component for triamcinolone acetonide which is apparently distributed intracellularly, largely as a cytoplasmic soluble macromolecule. The structure-activity relationships of steroids active in growth inhibition are exactly paralleled by their ability to displace 3H-triamcinolone acetonide from this binding component. The binding component is saturated between 10-8 and 5 x 10-8 M triamcinolone acetonide. The macromolecules bind unchanged triamcinolone acetonide noncovalently, and the steroid is released from binding by brief digestion with a proteolytic enzyme. Cells which are resistant to glucocorticoids bind much less triamcinolone acetonide in a specific manner (i.e., displaceable by glucocorticoids) than do sensitive cells. The binding component therefore satisfies many of the rigorous criteria necessary for assignment as a "receptor" for the growth-inhibitory action of glucocorticoids on mouse fibroblasts. In addition, triamcinolone acetonide bound to the 105,000 x g supernatant fraction remains bound under conditions of frozen storage for at least 1 month.
- Copyright ©, 1970, by Academic Press Inc.
MolPharm articles become freely available 12 months after publication, and remain freely available for 5 years.Non-open access articles that fall outside this five year window are available only to institutional subscribers and current ASPET members, or through the article purchase feature at the bottom of the page.
|