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.
Ripoll-Hamer
E
E
Centro de Pesquisa Básica, Instituto Nacional de Câncer, Rio de Janeiro, Brasil.
De-Paula
E F
EF
Freitas
L C
LC
Pereira
M J
MJ
Fonseca
L M
LM
Gutfilen
B
B
Carvalho
J J
JJ
Pôrto
L C
LC
Bernardo-Filho
M
M
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