ANTAGONISM BETWEEN ALKALOIDS AND SALTS IN 

 RELATION TO PERMEABILITY. 



By W. J. V. OSTERHOUT. 



{From the Laboratory of Plant Physiology, Harvard University, Cambridge.) 



(Received for publication, March 23, 1919.) 



Previous investigations'^ have led the writer to the view that salts 

 which have opposite effects on permeability are able to antagonize 

 each other. It seemed of interest to discover whether this is also 

 true of antagonism between salts and alkaloids. Such antagonism 

 has been reported by several authors, the most extensive investiga- 

 tion being that of Robertson. ^ 



In order to compare the antagonism between alkaloids and salts 

 with that between salts and salts, experiments were carried out under 

 precisely the same conditions in both cases. These experiments were 

 made by determining the electrical conductivity of Laminaria in a 

 manner previously described.^ 



Taking a typical case of salt antagonism, that of NaCl and CaCl2, 

 we find that NaCl produces an increase of permeability while CaCl2 

 produces a decrease (followed by an increase).^ We may therefore 

 expect that if alkaloids antagonize NaCl they will produce a de- 

 crease in permeability. 



The alkaloids studied were nicotine, caffeine, and cevadine. They 

 were added in varying amounts to NaCl 0.52 m,^ and their effect 

 upon the electrical conductivity of Laminaria y^diS determined. ^ 



1 Osterhout, W. J. V., Science, 1915, xli, 255. 



^ For the literature see Robertson, T. B., /. Biol. Chem., 1906, i, 507. Ergehn. 

 Physiol, 1910, x, 238, 311. Also Sziics, J., Jahrb. wiss. Bot., 1912, lii, 85. 



3 Osterhout, W. J. V., /. Biol. Chem., 1918, xxxvi, 485. 



4 Osterhout, W. J. V., Science, 1912, xxxv, 112. 



^ All the solutions had the same conductivity as sea water. 

 ® For the precautions used in preparing the material see Osterhout, W. J. V., 

 Proc. Am. Phil. Soc, 1916, Iv, 533. 



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