Estimation of Plasma Phosphatase by Determination of Hydrolysed Phenol with Amino-antipyrine

Abstract

Plasma phosphatase was first determined by Martland (1925) and then by Kay (1930), using glycerophosphate and estimating the inorganic phosphate liberated at 370 C. at a specified pH and in a given time.The procedure has been variously modified and simplified by Jenner and Kay (1932), Bodansky (1933), Shinowara, Jones, and Reinhart (1942).Several substrates, other than glycero- phosphate, have also been used, e.g., phenyl phos- phate (with determination of either the liberated phenol, King and Armstrong, 1934, or phosphate, King, Abul-Fadl, and Walker, 1951), nitro-phenyl phosphate (by the colour of the liberated nitro- phenol, Ohmori, 1937; King and Delory, 1939; Bessey, Lowry, and Brock, 1946), naphthyl phos- phate (by determination of naphthol by a diazo method, Seligman, Chauncey, Nachlas, Manheimer, and Ravin, 1951), phenolphthalein phosphate (by the colour of alkaline phenolphthalein, Bray and King, 1943; Huggins and Talalay, 1945).Of the.se procedures, the Bodansky (glycerophosphate) and the King-Armstrong (phenyl phosphate) are perhaps the most widely used.King and Armstrong (1934) determined free phenol, liberated from phenyl phosphate by the phosphatase, by either the Folin and Ciocalteu (1927) phosphomolybdic reagent or by the diazo reaction, and preferred the former.Both pro- cedures required the precipitation and removal of the plasma proteins subsequent to the hydrolysis of the substrate.In 1951 Grifols Lucas proposed a does not require precipitation and separation of the plasma proteins, with a consequent simplification and shortening of the estimation.