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BIOPHYSICAL FACTORS IN DRUG ACTION 



H. HURST, B.Sc, Ph.D. 

 Department of Colloid Science, Cambridge 



Introduction 



THE rapid advances which have been made within the past 

 few years in our knowledge of tissue ultrastructure and 

 cell chemistry have introduced new perspectives into the 

 possibilities of a better understanding of the various modes of 

 drug action, by closer collaboration between the biologist and 

 the chemist. Perhaps one of our chief difficulties in seeking a 

 rational explanation of the biological activities of drugs in terms 

 of simple physicochemical or biophysical factors is the apparent 

 simplicity of the relationships which may readily be deduced by 

 analogy w^th artificial model systems. The justification for the 

 use of such models has frequently been based on the assumption 

 that the living system is so complex that the gross properties 

 of a particular structure are often embodied in a simplified re- 

 constructed system. 



But the physiologist is now inclined to enquire a little further 

 into the intermediary factors which influence the production of 

 a biological response to a drug. The morphologist is becoming 

 increasingly interested in the dynamic significance of the struc- 

 tures he examines, and he is better acquainted with the uses 

 of the ultraviolet and electron microscopes in detecting struc- 

 tures which cannot be resolved with the ordinary light micro- 

 scope. Moreover he is able to interpret the molecular arrange- 

 ments in these structures with the polarization microscope and 

 the methods of X-ray difi"raction analysis. 



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