A histochemical method for demonstration of 2′ ,3′ -cyclic 3′ -phosphohydrolase activity

Summary A histochemical method for demonstration of 2′ ,3′-cyclic nueleotide 3′-phosphohydrolase activity is proposed. Cryostat sections, fixed in chlorophorm-methanol mixture, are incubated in a solution containing cyclic adenosine 2′ ,3′-monophosphate, acid phosphatase, lead nitrate in acetate buffer, p H = 6,4 or 6.5. This method is based on conversion by the 2′ ,3′ -cyclic nueleotide 3′ -phosphohydrolase of cyclic adenosine 2′ ,3′ -monophosphate to nueleotide- 2′-monophosphate. Under the action of exogenous acid phosphatase, inorganic phosphate is released. It precipitates as lead phosphate if lead ions are present. By adding yellow ammonium sulphide, the lead phosphate is converted to lead sulphide which is the visible reaction product.