| Abstract: | Abstract A very sensitive analytical technique is described for measuring phosphodiesterase (PDE) activity in mouse muscle, where levels of these enzymes are very low. After the action of PDE, a second enzyme, 5′nucleotidase, is employed to release inorganic phosphorus (Pi) which is assayed by a colorimetric method using malachite-green as dye solution. It is thus possible to measure very small amounts of Pi (0.1 – 0.5 μg) and to assay PDE activity with all the cyclic nucleotides even in the presence of methyl-xanthines. Phosphodiesterase assay in this manner gives a response that is linear with serial amounts of purified enzyme and different quantities of muscle homogenate. |
