The relation between biomechanics of conduit coronary artery and metab
olic processes in its wall were studied in cardiac pressure overload,
in anaesthetized dogs. Two sorts of forces and/or coronary deformation
s were followed: (1) radial and length deformation of ramus interventr
icularis anterior (RIA) due to ventricle volume changes, and (2) shear
stress in ramus circumflexus (RC) ensuing the blood flow changes. Inc
rease in aortic pressure (33.9 +/- 2.30%) accompanied an increase in R
IA diameter (4.6 +/- 0.38%) and an increase in segment length (8.0 +/-
1.0%) indicating that both circumferential and longitudinal oriented
muscle bundles were loaded. Increase in RC blood flow (55.6 +/- 4.0%)
and diameter (3.8 +/- 0.3%) resulted in an increase of shear stress (3
5.15 +/- 11.16%) that affects particularly the endothelial cells. Two
hours lasting cardiac load suggested a tendency, 4 h lasting load resu
lted in a significant increase both in RNA content (11.06 +/- 4.68% an
d 9.05 +/- 0.72%) and in [C-14]leucine incorporation (53.59 +/- 13.75%
and 48.41 +/- 16.16%) in the myocardium and RIA wall, respectively. N
o change was found in RC wall. The process was reversible, 2 h after t
he load had ceased. The heterogeneity of metabolic processes reflected
closely the heterogeneity in coronary deformation.