Permeation of large lipophilic molecules—steroid transport

Permeation of large lipophilic molecules—steroid transport 

To test whether the barrier for steroids was the same as the barrier for the smaller solutes, Giorgi also measured the permeabilities and partition coefficients for some smaller molecules. Some of these data are reproduced in Fig. 10 as a log/log plot of permeabihty coefficients against n-octanol partition coefficients. Clearly the data for the small solutes and for the steroids fall on a fairly good straight line, suggesting that the same rate law holds for the permeation of the steroids as for that of the smaller solutes. All seem to encounter a rate-limiting permeability barrier which has 

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Permeation of large lipophilic molecules—steroid transport... 

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