Abstract
A new cell culture model that better mimics the permeability of the human small intestine was developed for studies of passive drug transport. The intestinal epithelial cell line, 2/4/A1, conditionally immortalized with a temperature-sensitive mutant of the growth-promoting oncogene simian virus 40 (SV40) large T, was grown on permeable supports. The cells grew at 33°C, where the oncogene is fully active, but stopped growing and entered a differentiation program at 39°C, where the oncogene is inactive. Significant cell death was observed at 39°C and, therefore, growth conditions under which 2/4/A1 cells survive during the differentiation process were developed. Cells grown on extracellular matrices which contained laminin at an intermediate temperature of 37°C formed viable differentiated monolayers with tight junctions, an increased expression of brush border enzymes, and a paracellular permeability that was comparable to that of the human small intestine. The permeability of 17 structurally diverse drugs gave a sigmoidal relationship with the absorbed fraction of the drugs after oral administration to humans. The relationship was compared with those obtained with the well established Caco-2 model and after in vivo perfusion of the human jejunum. The transport of drugs with low permeability in 2/4/A1 monolayers was comparable to that in the human jejunum, and up to 300 times faster than that in Caco-2 monolayers. The transport of drugs with high permeability was comparable in all models. These results indicate that 2/4/A1 monolayers are promising alternatives to Caco-2 monolayers for studies of passive drug transport.
Footnotes
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Send reprint requests to: Dr. Per Artursson, Department of Pharmacy, Division of Pharmaceutics, Uppsala University, Box 580, SE-751 23 Uppsala, Sweden. E-mail:per.artursson{at}galenik.uu.se
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↵1 This work was supported by Grant 95-58 from Centrala Försöksdjursnämnden, Grant 9478 from The Swedish Medical Research Council, The Swedish Fund for Scientific Research without Animals, and ASTRA AB. Preliminary results of this study were published previously as meeting abstracts: Pharm Res(1997); 14 (Suppl.):27 and Ann NY Acad Sci(1998); 859:198–200.
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↵2 S.T. and V.M. contributed equally to this paper.
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↵3 Present address: Gastroenterology Division, 2nd Department of Medicine, Johann Wolfgang Goethe University, Frankfurt, Germany.
- Abbreviations:
- SV40
- simian virus 40
- ECL
- a mixture of the extracellular matrices entactin, collagen IV, and laminin
- HBSS
- Hanks’ balanced salt solution
- PEG
- polyethylene glycol
- RMSE
- root mean square error
- TER
- transepithelial electrical resistance
- Received January 21, 1999.
- Accepted May 8, 1999.
- The American Society for Pharmacology and Experimental Therapeutics
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