Studies concerning the Nature of the Secretory Activity of the Isolated Ringer-perfused Frog Liver Ii. the In~itory and the Promoting Influence of Organic Elec- Trolytes and Non-electrolytes upon the Secretion of Dyestd'ffs $ by Rudolf Hober and Elinor Moore

As described in the preceding paper (H6ber (1)), the isolated Ringerperfused frog liver is characterized by its ability to collect from the circulating fluid a great number of dyestuffs to such a degree that they appear in the secretion many hundred times concentrated. Now, this activity of the surviving gland can be abolished temporarily in a very striking way by substituting in the perfusion fluid 1/8 to 1/10 of the NaC1 with the isosmotic amount of certain organic non-electrolytes or electrolytes. After a short time the color of the secretion fades, often completely, but reappears after resumption of peffusion with Ringer (H~ber (2), Valdecasas (3)). Nonelectrolytes producing this inhibitory influence are chiefly the disaccharides, hexoses, pentoses, and hexahydric, pentahydric, and lower polyhydric alcohols as well as amino acids and succinamide. Electrolytes acting in the same way are the sodium salts of the lower fatty acids (acetate, propionate), of lactic acid, and of amino dicarboxyllc acids. I t appears that all these inhibitory substances have a strong hydropolarity and therefore lack surface activity. The opposite action, promotion of the secretory power of the liver, has been known for a long time to be exerted by salts of the bile acids. A similar effect has been observed with some anesthetics, with saponin, and with salts of some organic bases and of some higher fatty acids. In contrast to the group of inhibiting agents these substances are characterized by surface activity. Investigation of their influence pre-