Stoll K E, Ottino P, Duncan J R
Department of Biochemistry and Microbiology, Rhodes University, Grahamstown, South Africa.
Prostaglandins Leukot Essent Fatty Acids. 1994 Mar;50(3):123-31. doi: 10.1016/0952-3278(94)90094-9.
Previous studies have shown that ascorbate (Asc) supplementation affects arachidonic acid (AA) and prostaglandin E2 (PGE2) levels in B16 murine melanoma cells. In this study, non-malignant LLCMK cells and malignant B16 cells were respectively supplemented with 20 microCi 15-3H AA, to investigate whether these two cell types were able to take up AA from the media. Furthermore, these cells were also supplemented with Asc (0-100 micrograms/ml) to determine the effect of Asc supplementation on 15-3H AA uptake. Both cell types incorporated 15-3H AA, while Asc supplementation enhanced this 15-3H AA uptake. To determine the site of the AA incorporation, both cell types were supplemented with 2.5 microM AA and Asc (0-100 micrograms/ml). The % AA composition of the stroma fractions of both cell types was increased with 100 micrograms/ml Asc supplementation. Supplementation of these cells with AA (0-50 microM) resulted in an increase in PGE2 levels in the B16 cells. Since PGE2 has been shown, in turn, to stimulate adenylate cyclase (AC) activity, the LLCMK and B16 cells were supplemented with 0-100 microM PGE2. A 3-fold increase of AC activity in the B16 cells occurred as a result of this supplementation.
先前的研究表明，补充抗坏血酸（Asc）会影响B16小鼠黑色素瘤细胞中花生四烯酸（AA）和前列腺素E2（PGE2）的水平。在本研究中，分别向非恶性LLCMK细胞和恶性B16细胞中添加20微居里的15-3H AA，以研究这两种细胞类型是否能够从培养基中摄取AA。此外，还向这些细胞中添加了Asc（0-100微克/毫升），以确定补充Asc对15-3H AA摄取的影响。两种细胞类型均摄取了15-3H AA，而补充Asc增强了这种15-3H AA的摄取。为了确定AA掺入的位点，向两种细胞类型中均添加了2.5微摩尔/升的AA和Asc（0-100微克/毫升）。补充100微克/毫升的Asc后，两种细胞类型的基质部分的AA组成百分比均增加。向这些细胞中添加AA（0-50微摩尔/升）导致B16细胞中PGE2水平升高。由于已证明PGE2反过来会刺激腺苷酸环化酶（AC）的活性，因此向LLCMK和B16细胞中添加了0-100微摩尔/升的PGE2。补充后，B16细胞中的AC活性增加了3倍。
