Immunoinhibition assay of the serum activity of human glycogen isophosphorylase BB in the diagnosis of the acute myocardial ischaemia.

Polyclonal rabbit anti-human isophosphorylases inhibit selectively the isoenzyme activities of the BB and MM isoenzyme of the human glycogen phosphorylase b with high sensitivity and without crossreactivities. On this basis a serological immunoinhibition assay of the BB isoenzyme in the range of 1-125 nmol s-1 l-1 is described. Preliminary clinical results indicate the BB isoenzyme as a sensitive and specific marker of the acute myocardial ischaemia including bypass surgery and suggest a substantial improvement of the differential diagnosis of infarction.