Simplified and efficient labeling of human platelets in plasma using indium-111-2-mercaptopyridine-N-oxide: preparation and evaluation.
The need for a gamma-emitting radioactive agent that will label platelets in plasma efficiently by a procedure that can be used uniformly in each laboratory is well recognized. A water soluble sodium salt of 2-Mercaptopyridine-N-oxide (Merc) was evaluated that quantitatively chelated 111ln at a pH range of 0.7 to 7.4, and allowed greater than 80% incorporation of 111ln in platelets in plasma. This was dependent on pH, Merc concentration, and platelet concentration. Platelets were labeled using either preformed [111ln]Merc or incubating platelets with 2.5 micrograms dry Merc first and then with 111ln. The latter method provided a simple kit procedure that labeled platelets with negligible alteration of in vitro aggregability. In dogs, labeled platelets had normal survival (7.5 days), 66 +/- 6.6% recovery, detected vascular thrombi (thrombi/blood = 59.4), and pulmonary emboli (PE/blood = 46.2) by scintigraphy. In the kit procedure, the use of Merc compared favorably to that of oxine and tropolone.
D000818:Animals; D001792:Blood Platelets; D002470:Cell Survival; D004285:Dogs; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007204:Indium; D007553:Isotope Labeling / Q000379:methods; D010974:Platelet Aggregation; D011655:Pulmonary Embolism / Q000000981:diagnostic imaging; D011725:Pyridines; D011868:Radioisotopes; D011877:Radionuclide Imaging; D011933:Reagent Kits, Diagnostic; D013871:Thiones; D013924:Thrombophlebitis / Q000000981:diagnostic imaging
D011725:Pyridines; D011868:Radioisotopes; D011933:Reagent Kits, Diagnostic; D013871:Thiones; D007204:Indium; C008704:pyrithione