ISSN:
1619-7089
Keywords:
Technetium-99m 2,3-dimercaptopropionylhuman serum albumin
;
Ventriculography
;
Technetium-99m-labelled red blood cells
Source:
Springer Online Journal Archives 1860-2000
Topics:
Medicine
Notes:
Abstract Technetium-99m labelled red blood cells (99mTc-RBCs) are the standard radiopharmaceutical for radionuclide ventriculography but suffer from some practical disadvantages such as risk of viral contamination and lengthy preparation (in vitro labelling) or poor labelling efficiency due to patient medication interactions (in vivo labelling). 99mTc-labelled human serum albumin (HSA) is not really a valuable alternative as the activity diffuses too rapidly out of the vascular space due to the weak binding of the radionuclide. We have modified HSA by reaction with N-hydroxysuccinimidyl 2,3di(S-acetylmercapto)propionate (SAMP) to introduce a varying number of 2,3-dimercaptopropionyl (DMP) side chains. The resulting DMP-HSA can be rapidly labelled with 99mTc at room temperature by simple addition of stannous ions and eluate of a 99mTc generator. After evaluation in mice and rabbits, two different 99mTc-DMP-HSA preparations — obtained after reaction of SAMP with albumin in a molar ratio of, respectively, 8:1 and 16:1 — were tested in a volunteer and compared to 99mTcRBCs. The blood time-activity curves of the three preparations were quite similar but both 99mTc-DMP-HSA preparations were excreted much less into the urine than 99mTc-RBCs. Ventriculography was performed with the three tracer agents, each time with a 1-week interval. In the three studies, the heart was clearly visualized and the left and right ventricle could be easily delineated. The ejection fractions obtained after administration of the three preparations were similar. With both 99mTc-DMP-HSA preparations the low activity in the spleen was a distinct advantage and facilitated delineation of the left ventricle. However, a slightly higher liver uptake was seen with 99mTc-DMP-HSA 16:1, whereas the liver uptake of 99mTc-DMP-HSA 8:1 and 99mTc-RBCs was the same. These first results suggest that 99mTc-DMP-HSA, and in particular 99mTc-DMP-HSA 8:1, could be used for ventriculography as a practical and reliable alternative to 99mTc-RBCs.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00238113
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