Hormone defined

FGF), and hydrocortisone to grow serum free (see Table 4) (Hutchings and Sato, 1978). Both of these cell types can grow serum free with appropriate supplements at the same rate as that obtained in serum-supplemented medium. Both cell types can also survive over extended culture periods in hormonally defined serum-free medium. 

Figure 10. Primary cultures of mouse kidney cells. Primary cultures of kidney epithelial cells derived from 10-day-old mice were grown either in hormonally defined medium with five supplements (5 pg/ml insulin, 5 pg/ml transferrin, 25 ng/ml PCE, 5 X10" M hydrocortisone, and 5 x 10" M Tj), or in medium supplemented with 10% fetal calf serum. After 10 days, primary cultures still were epithelial in morphology serum free (a) but were overgrown with fibroblasts with serum (b). (Taub et al., 1979 with permission.)...

Taub, M., Chuman, L., Saier, M.H., Sato, G. (1979). Growth of a kidney epithelial cell line (MDCK) in hormonally defined serum-free medium. Proc. Natl. Acad. Sci. USA 76, 3338-3342. 

Chung, S.D., Alavi, N., Livingston, D., Hiller, S. and Taub, M. (1982). Characterization of primary rabbit kidney cultures that express proximal tubule functions in a hormonally defined medium. J Cell Biol. 95 118-126. 

Enat, R., Jefferson, D.M., Ruiz-Opazo, N., Gatmaitan, Z., Leinwand, L.A. and Reid, L.M. (1984). Hepatocyte proliferation in vitro Its dependence on the use of serum-free hormonally defined medium and substrata of extracellular matrix. Proc. Natl. Acad. Sci U.S.A. 81 1411-1415. 

Immortalization of human hepatocytes would help to overcome the hmited availability of human cells, thereby avoiding the use of mahgnant-derived cell hnes however, care will still be required with these cells. A better approach would be to develop methods for the culture of primary human hepatocytes using hormonally defined media containing growth factors in which cells are stimulated to undergo division. 

Epithelial cells are cells covering the body surface and bounding cavities, e.g. the gut or kidney tubules. They are bound together laterally by tight junctions to form sheets of cells and their apical and basolateral surfaces differ in composition and are kept apart by the tight junctions. They have the ability to transport solutes across the cell sheet from the apical surface. Of course, in culture a single epithelial cell cannot exhibit these properties but as the cells divide they form stable clusters of tightly associated cells and monolayers of such cells do show polarity. This is most easily achieved in serum-free, hormonally defined medium ( 5.8) when differentiated... 

CLARK, J. (1983) In Hormonally Defined Media, Fischer, G. and Wieser, P.J. (eds.) (Springer-Verlag, Berlin) p. 6. 

HAM, R.G. (1983) In Growth of Cells in Hormonally Defined Media, Vol. 9 (Cold Spring Harbor Conference on Cell Proliferation), Sato, G.H., Pardee, A.B. and Sirbascu, D.A. (eds.) (Cold Spring Harbor Labs.) p. 39. 

Ham RG (1982) Importance of basal nutrient medium in the design of hormonally defined media. In Sato GH, Pardee AB Sirbasku (eds) Growth of Cells in Hormonally Defined Media, pp. 39-60. Cold Spring Harbor Press, Cold Spring Harbor, New York. 

The conditions of cell culture are critical for chemical testing. Particular attention must be given to the medium used for the cultivation of cells. While the use of serum, usually foetal bovine serum (FBS), has long been customary to provide isolated cells with a pool of nutrients, attachment factors, and hormones, several issues are encouraging scientists to move towards serum-free hormonally defined medium [53]. In particular, the composition of FBS varies from batch to batch, rendering highly discriminative analyses such... 

There have been several investigations into the use of hormonally defined medium in order to maintain the differentiation of primary cells, as it is suspected that serum may be a factor in dedifferentiation. The application of defined medium also allows a more standardized approach to cell culture delivering greater reproducibility and transferability. For renal tubular epithelial cells defined medium supplements have been described as far back as 1982 [148], We have been, over the last number of years, successfully cultivating human renal proximal tubular cells (primaries and cell lines) in serum free hormonally defined medium containing EGF, hydrocortisone, insulin, transferrin, and sodium selenite using DMEM-Hams F12 as the base medium [36, 112, 114, 149], Both the HK-2 cell line and the RPTEC/TERT1 have been developed in serum-free conditions. 

Courjault-Gautier F et al (1995) Consecutive use of hormonally defined serum-free media to establish highly differentiated hitman renal proximal tubule cells in primary culture. J Am Soc Nephrol 5(11) 1949-1963... 

Additionally, efforts need to be invested to establish culture medium formulations, which are designed to maintain differentiated, quiescent cultures. At present this criteria are best, although still insufficiently, met by serum free hormonally defined media. 

Potential limitations include the tendency for primary cells in culture to dedifferentiate and lose functional expression of enzymes and membrane transporters during the course of culture. For example, expression of enzymes important for drug metabolism, such as CYPs, tends to readily decrease if culture conditions are not optimized. Plasma membrane transporters, such as many of the OATs, can readily internalize and become nonfunctional dining the course of cultme (Lash et al, 2006). Our strategy to counteract these potential problems has been to use the serum-free, hormonally defined medium that has become standard with primary culture of epithelial cells and then add other supplements to optimize maintenance of differentiated fnnction (Lash et al., 1995 Lash, 2012). 

For the cultivation of airway epithelial cells, the cells are usually plated onto tissue culture plates coated with collagen or extracellular matrix components. Hormonally defined Ham s F12 medium contained 1 % penicillin-streptomycin, 5 ig/ml insulin, 5 ig/ml transferrin, 25 ng/ml epidermal growth factor, 15 ig/ml epithehal growth factor supplement, 2 X 10" M triiodothyronin, and 10" M hydrocortisone. 

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