TY - JOUR T1 - STUDIES ON THE TOXICITY AND PHARMACOLOGY OF RIBOFLAVIN JF - Journal of Pharmacology and Experimental Therapeutics JO - J Pharmacol Exp Ther SP - 75 LP - 80 VL - 76 IS - 1 AU - KLAUS UNNA AU - JOSEPH G. GRESLIN Y1 - 1942/09/01 UR - http://jpet.aspetjournals.org/content/76/1/75.abstract N2 - 1. The L.D. 50 of riboflavin in rats following intraperitoneal administration is 560 mgm. per kgm. Death occurs within 2 to 5 days with signs of anuria and azotemia and is due to obstruction of the kidney by concretions. 2. Oral administration of riboflavin to rats (10 grams per kgm.) and to dogs (2 grams per kgm.) failed to produce any toxic effects. The low solubility of riboflavin prevents its absorbtion from the gastro intestinal tract in amounts sufficient to produce toxic effects. 3. Daily administration of riboflavin over periods of 4 months to rats (10 mgm.) and dogs (25 mgm. per kgm.) failed to produce any toxic manifestations. Rats receiving 10 mgm. daily were raised through 3 generations. 4. The metabolism, the circulatory and respiratory systems, and isolated smooth muscle organs of animals maintained on adequate diets are not influenced by riboflavin. ER -