title: Considerations in use of microspheres for myocardial blood-flow measurements in long-term experiments on rats.
abstract: The loss of 15-micron radioactive microspheres from rat myocardium was determined in long-term experiments. Heterotopic heart transplantation was used for the evaluation of microsphere losses. Microspheres were injected into the left ventricle of a donor rat, and the number of microspheres entrapped in the heart was measured after its isolation. The heart was transplanted into the abdominal cavity of a recipient rat and left there for 1-3 wk. The number of microspheres entrapped in the donor heart before the transplantation was compared with the number of microspheres remaining there after 1-3 wk. The losses of radioactivity from the myocardium over 1-3 wk did not exceed 10%. In a control series of experiments, the loss of radioactivity from the microspheres placed in microporous capillaries implanted subcutaneously into rats was determined. The measured leach criterion in vivo was 0.58% instead of 0.30% indicated by the manufacturer for in vitro conditions. The loss of 15-micron microspheres from the rat myocardium taking into account the leach criterion in vivo was 1.54 +/- 1.64%.
authors.affiliation: Department of Experimental Pharmacology, Cardiology Research Center, Moscow, USSR.
authors.forename: O S
authors.initials: OS
authors.lastname: Medvedev
authors.forename: E R
authors.initials: ER
authors.lastname: Martynova
authors.forename: R S
authors.initials: RS
authors.lastname: Akchurin
authors.forename: V Y
authors.initials: VY
authors.lastname: Khalatov
mesh_terms: D000818:Animals; D003326:Coronary Circulation; D016027:Heart Transplantation; D008297:Male; D008863:Microspheres; D011868:Radioisotopes; D051381:Rats; D011919:Rats, Inbred Strains; D012538:Scandium
chemical_list: D011868:Radioisotopes; D012538:Scandium