In vitro radioautographic studies of the biodistribution of radiopharmaceuticals on blood elements.
In the present study we evaluated the binding of the radiopharmaceuticals sodium pertechnetate (Na 99mTcO4), methylenediphosphonic acid (99mTc-MDP) and glucoheptonate acid (99mTc-GHA) to blood elements using centrifugation and radioautographic techniques. Heparinized blood was incubated with the labelled compounds for 0, 1, 2, 3, 4, 6 and 24 h. Plasma (P) and blood cells (BC) were isolated and precipitated with 5% trichloroacetic acid (TCA), and soluble (SF) and insoluble fractions (IF) were separated. Blood samples were prepared (0 and 24 h) and coated with LM-1 radioautographic emulsions and percent radioactivity (%rad) in P and BC was determined. The binding of Na 99mTcO4 (%rad) to P was 61.2% (0 h) and 46.0% (24 h), and radioautography showed 63.7% (0 h) and 43.3% (24 h). The binding to BC was 38.8% (0 h) and 54.0% (24 h), and radioautography showed 36.3% (0 h) and 56.7% (24 h). 99mTc-MDP study presented 91.1% (0 h) to P and 87.2% (24 h), and radioautography showed 67.9% (0 h) and 67.4% (24 h). The binding to BC was 8.9% (0 h) and 12.8% (24 h), and radioautography showed 32.1% (0 h) and 32.6% (24 h). 99mTc-GHA study was 90.1% (0 h) to P and 79.9% (24 h), and radioautography showed 67.2% (0 h) and 60.1% (24 h). The binding to BC was 9.9% (0 h) and 20.1% (24 h), and radioautography showed 32.8% (0 h) and 39.9% (24 h). The comparison of the obtained results suggests that the binding to plasma and blood cells in the two techniques used (radioautography and centrifugation) is qualitatively in accordance.
Centro de Pesquisa Básica, Instituto Nacional de Câncer, Rio de Janeiro, Brasil.
E
E
Ripoll-Hamer
E F
EF
De-Paula
L C
LC
Freitas
M J
MJ
Pereira
L M
LM
Fonseca
B
B
Gutfilen
J J
JJ
Carvalho
L C
LC
Pôrto
M
M
Bernardo-Filho
D000818:Animals; D001345:Autoradiography / Q000379:methods*; D001773:Blood Cells / Q000737:chemistry*; D002498:Centrifugation; D063065:Organophosphonates / Q000097:blood* / Q000493:pharmacokinetics*; D019275:Radiopharmaceuticals / Q000097:blood* / Q000493:pharmacokinetics*; D051381:Rats; D017208:Rats, Wistar; D013670:Sodium Pertechnetate Tc 99m / Q000097:blood* / Q000493:pharmacokinetics*
D063065:Organophosphonates; D019275:Radiopharmaceuticals; D013670:Sodium Pertechnetate Tc 99m