MECHANICAL-PROPERTIES OF PORCINE SMALL CORONARY-ARTERIES IN ONE-KIDNEY, ONE-CLIP HYPERTENSION

The purpose of this study was to analyse the mechanical properties of small coronary arteries from pigs with one-kidney, one-clip hypertensi on and normotensive control animals and to determine whether these cou ld contribute to vascular structural changes observed in hypertension. Small coronary artery wall tension-internal circumference relationshi ps were determined for coronary arteries mounted in a myograph and use d to calculate incremental elastic modulus-stress relationships for ar teries from normotensive and hypertensive pigs. Wall tension-internal circumference relationships were shifted to the left in arteries from hypertensive pigs, but the stress-strain and incremental elastic modul us-stress relationships were not influenced by the increased blood pre ssure load. These data indicate that small coronary arteries from hype rtensive pigs are not less distensible than those from normotensive co ntrols. Therefore the previously reported increased media thickness:lu men diameter ratios in coronary arteries in this model of hypertension are not a consequence of abnormal elastic properties and can be ascri bed to a remodelling process.