Cor Vasa 2006, 48(10):334-339 | DOI: 10.33678/cor.2006.110

Distribution of labeled bone marrow mononuclear cells in the post-ischemic myocardium (an ex vivo model of the rabbit heart)

Peter Scheer^1,*, Martin Klabusay¹, Kristína Řeháková¹, Michael Doubek², Leoš Křen³, Stanislav Palša², Jaroslava Beránková¹, Drahomír Horký⁴, Jiří Mayer⁵, Jaroslav Meluzín⁶, Jaroslav Doubek¹

¹ Ústav fyziologie, Fakulta veterinárního lékařství, Veterinární a farmaceutická univerzita Brno

² Laboratoř flow cytometrie a celulární terapie, Interní-hematoonkologická klinika

³ Ústav patologie, Fakultní nemocnice Brno

⁴ Ústav histologie a embryologie, Lékařská fakulta Masarykovy univerzity

⁵ Interní-hematoonkologická klinika, Fakultní nemocnice Brno

⁶ I. interní-kardioangiologická klinika, Fakultní nemocnice u sv. Anny, Brno, Česká republika

Background/aims:
Experiments in stem cell treatment of myocardial infarction (MI) require a model with ideally ischemic lesion and intravascular application of cells. The goal of our trial was to induce sub-lethal MI in rabbit to prove the ability of iron labeled mononuclear cells (IL-MNC) from bone marrow to migrate into the injured myocardium and to evaluate the short-term distribution of intravascularly administered cells in the damaged left ventricle.

Material and methods:
Sub-lethal MI was induced successfully in 14 rabbits using 18-hour ligation of diagonal branches of the left anterior descending coronary artery (in vivo interposition). For study of distribution of transplanted IL-MNC, we used a model of isolated heart with perfusion according to Langendorf (ex vivo interposition). A total of 1.48 million of IL-MNC were administered into the coronary arteries of each rabbit over 4 minutes. Isolated hearts were divided into 4 groups: control group K (n = 4), where IM was not induced and 10-minute perfusion with isotonic Krebs-Henseleit solution was applied after IL-MNC infusion, group P1 (n = 4) with 2-minute perfusion, P2 (n = 6) with 10-minute perfusion, and P3 (n = 4) with 25-minute perfusion. Myocardial histology was performed after perfusion from MI zones (I) and non-MI zones (nI). Numbers of IL-MNC in the histological slides were determined semi-quantitatively from 15 randomized viewing fields in vessels (V), myocardial interstitial tissue (MIT), and altogether (T).

Results:
Median (min, max) of numbers of detected IL-MNC from MI zones in groups K [nI = 0,5 (0.1), I = 1 (0.2)] and P1 [nI = 2 (1.2), I = 1 (0.3)] were significantly lower when compared with groups P2 [nI = 1.5 (0.18), I = 27 (19.37)] and P3 [nI = 11 (0.19), I = 22 (18.25)]. There were no significant differences in non-MI zones in comparison of IL-MNC numbers in vessels and myocardium among all groups (K, P1, P2, P3), except of comparison of total cell number in P3 vs. K (p = 0.019) and P3 vs. P1 (p = 0.019). In MI zones, significantly more cells were intercepted in group P2 vs. controls (V p = 0.009, MIT p = 0.020 and T p = 0.010) and in group P3 vs. controls (V p = 0.018, MIT p = 0.032, T p = 0.020).

Conclusion:
In all animals, we successfully induced MI to an extent allowing analysis of IL-MNC migration. Iron-labeled mononuclear cells from bone marrow were able to migrate into myocardial interstitial space with significantly enhanced affinity to injured tissue.

Keywords: Myocardial infarction; Stem cells; Iron labeling; Animal model; Rabbit

Published: October 1, 2006  Show citation