TREATMENT OF STATE REQUIRING INCREASED OXYGEN UTILITY TO TISSUE OF MAMMAL

PURPOSE: To obtain a composition including a specific naphthoic acid derivative, and facilitating a suitable supply of the oxygen necessary for metabolism to a human tissue by changing the compatibility of hemoglobin to oxygen. CONSTITUTION: This composition includes an effective amount of a compound of formula I [R is H, an alkyl, an aryl or an aminoalkyl; R1 is H, an alkyl, NH2 , NR3 R4 (R3 and R4 are each H or an alkyl, or form a cyclic amino by bonding each other with N); R2 is H, an acyl, an aminoacyl, an alkyl (substituted by an aryl, a cycloalkyl, an alkoxy, etc.); A is H, halo, CF3 , OH, a group of formula II, an aminoalkyl, an aryl, an acyl, etc.] or its salt, e.g. 5-fenetoxy-3- hydroxy-2-naphthoic acid admixed with a pharmaceutically acceptable carrier. The compound inhibits an enzyme of 2,3-diphosphoglycerate phosphatase and allows 2,3-diphosphoglyceric acid to e maintained and accumulated in red blood corpuscles accompanied with holding and enhance of oxygen availability.