SUMMARY 1. The effects of various compounds on the fluorescence of microsome‐bound 1‐anilino‐8‐naphthalene sulphonate (ANS) have been studied. 2. Cationic drugs and divalent metal cations enhance the fluorescence of microsome‐bound ANS whereas anionic drugs and primary aliphatic alcohols decrease it. 3. No changes were observed in the fluorescence lifetime or emission maximum of ANS and it was concluded that there were no significant changes in the quantum yield of ANS fluorescence. 4. The changes in fluorescence are shown to be related to changes in ANS binding. 5. The results suggest that drug‐induced changes in the binding of ANS to the microsomal membrane reflect a change in the net charge on the membrane as a result of the binding of a charged drug and that changes in ANS fluorescence cannot be directly interpreted as changes in the structure of the membrane. 6. Primary aliphatic alcohols displace ANS from the microsomal membrane but cause no change in quantum yield. It is suggested that the alcohols change the net charge on the membrane either by exposure of negative charges or occlusion of positive charges. 7. The changes in ANS fluorescence can be used as a measure of the interaction of various drugs with the microsomal membrane. Apparent binding constants determined by this method for various drugs fall in the concentration ranges over which the drugs are reported to induce changes in membrane function in various in vitro systems.
|Number of pages||13|
|Journal||Clinical and Experimental Pharmacology and Physiology|
|Publication status||Published - Oct 1974|
- 1‐anilino‐8‐naphthalene sulphonate
- fluorescence probe technique
- membrane structure
- metal ions
- microsomes—rat liver.