AJP - Heart and Circulatory Physiology, Vol 242, Issue 6 1031-H1037, Copyright © 1982 by American Physiological Society
DNA synthesis in coronary collaterals after coronary artery occlusion in conscious dog
S. Pasyk, W. Schaper, J. Schaper, K. Pasyk, G. Miskiewicz and B. Steinseifer
With [3H]thymidine, DNA synthetic activity in coronary collateral
arterioles was assessed in dogs subjected to progressive stenosis of the
left circumflex coronary artery for different periods (36 h-5 days).
Coronary flow, reactive hyperemia, and pressure gradient (aortic pressure,
peripheral coronary pressure) were measured. Normal animals and animals
with sham operations served as controls. Labeling of nuclei was seen in
seven of the constricted dogs. Proliferative activity was highest at the
level of the smallest diameters of the collateral vessels (midzone). There
was heavy labeling in intima and media. Adventitial and myocardial
mesenchymal cells also incorporated [3H]thymidine. No radioactive DNA was
found in control animals. The data suggest that the active growth process
in collaterals after constriction of the left circumflex coronary artery
appears early, as there is evidence of collateral growth after 36 h of
constriction. Peak growth as evidenced by [3H]thymidine incorporation was
reached when the occlusion period was 4 days.
