Effects of sympathetic nerves on collateral vessels in the limb of atherosclerotic primates.
This study was performed to examine effects of sympathetic nerves on collateral vessels in the limb. We studied normal (N) and atherosclerotic (AS) cynomolgus monkeys that were fed atherogenic diet for 21 months. A common iliac artery was ligated 13 months before hemodynamic measurements. Using histofluorescence microscopy, a plexus of noradrenergic nerves was identified in the adventitia of collateral vessels. We measured blood flow to the limb with microspheres, and the pressure gradient from aorta to the iliac artery beyond the occlusion. The lumbar sympathetic chain was stimulated electrically at 3 Hz (SNS-3) and 15 Hz (SNS-15). In normal monkeys, conductance of collateral vessels (in ml/min per 100 g per 100 mm Hg) was 19 +/- 3.6 (mean +/- SE) during control, 14 +/- 1.6 during SNS-3, and 9.8 +/- 0.9 during SNS-15 (P less than 0.05 vs control). In AS monkeys, collateral conductance was 12 +/- 2.9 during control, 7.5 +/- 1.7 during SNS-3 and 3.9 +/- 1.8 during SNS-15 (P less than 0.05). In summary, collateral vessels in the limb are innervated and sympathetic stimulation produces pronounced constriction of collateral vessels in both normal and atherosclerotic monkeys. Thus, the effectiveness of collateral vessels in maintaining blood flow to the limb may be compromised by increased activity of sympathetic nerves.
Lopez
J A
JA
Department of Internal Medicine, University of Iowa College of Medicine, Iowa City.
Piegors
D J
DJ
Armstrong
M L
ML
Heistad
D
D
D000818:Animals; D001158:Arteries / Q000473:pathology; D001161:Arteriosclerosis / Q000097:blood / Q000473:pathology / Q000503:physiopathology*; D002784:Cholesterol / Q000097:blood; D003097:Collateral Circulation / Q000502:physiology*; D004558:Electric Stimulation; D006614:Hindlimb / Q000098:blood supply*; D007083:Iliac Artery; D008026:Ligation; D008252:Macaca fascicularis; D008297:Male; D012039:Regional Blood Flow; D013564:Sympathetic Nervous System / Q000503:physiopathology*
D002784:Cholesterol