Effects of chronic sympathectomy on locally mediated cutaneous vasodilation in humans

• Published in: Journal of applied physiology (1985) Vol. 92; no. 2; pp. 685 - 690
• Main Authors: Charkoudian, Nisha, Eisenach, John H, Atkinson, John L. D, Fealey, Robert D, Joyner, Michael J
• Format: Journal Article
• Language: English
• Published: Bethesda, MD Am Physiological Soc 01.02.2002; American Physiological Society
• Subjects: Adult; Biological and medical sciences; Blood; Dermatology; Endothelium - physiology; Female; Forearm - blood supply; Forearm - innervation; Fundamental and applied biological sciences. Psychology; Hot Temperature; Humans; Hyperhidrosis - physiopathology; Hyperhidrosis - surgery; Leg - physiopathology; Lower Body Negative Pressure; Male; Nervous system; Peripheral nervous system. Autonomic nervous system. Neuromuscular transmission. Ganglionic transmission. Electric organ; Reference Values; Regional Blood Flow; Skin; Skin - blood supply; Sympathectomy; Time Factors; Vasodilation - physiology; Vertebrates: nervous system and sense organs; Human; Regional blood flow; Autonomic nervous system; Innervation; Skin; Hemodynamics; Sympathetic nervous system; Vasodilation
• ISSN: 8750-7587; 1522-1601
• DOI: 10.1152/japplphysiol.00758.2001

Departments of 1  Anesthesiology, 2  Neurologic Surgery, and 3  Neurology, Mayo Clinic, Rochester, Minnesota 55905 In human skin, the vasodilator response to local heating includes a sensory nerve-dependent peak followed by a nadir and then a slower, nitric oxide-mediated, endothelium-dependent vasodilation. To investigate whether chronic sympathectomy diminishes this endothelium-dependent vasodilation, we studied individuals who had previously undergone surgical T 2 sympathectomy ( n  = 9) and a group of healthy controls ( n  = 8). We assessed the cutaneous vascular response (laser-Doppler) to 30 min of local warming to 42.5°C on the ventral forearm (no sympathetic innervation) and the lower legs (sympathetic nerves intact). Lower body negative pressure (LBNP) was measured to confirm sympathetic denervation. During local warming in sympathectomized individuals, vascular conductance reached an initial peak at both sites [achieving 1.73 ± 0.22 laser-Doppler units (LDU)/mmHg in the forearm and 1.92 ± 0.21 LDU/mmHg in the leg]. It then decreased to a nadir in the innervated leg [to 1.77 ± 0.23 LDU/mmHg ( P  <   0.05)] but not in the sympathectomized arm (1.69 ± 0.21 LDU/mmHg; P  > 0.10). The maximal vasodilation seen during the slower phase was not different between limbs or between groups. Furthermore, LBNP caused a 44% reduction in forearm vascular conductance (FVC) in control subjects, but FVC did not decrease significantly in sympathectomized individuals, confirming sympathetic denervation. These data indicate that endothelial function in human skin is largely preserved after sympathectomy. The altered pattern of the response suggests that the nitric oxide-dependent portion may be accelerated in sympathectomized limbs. regional blood flow; skin; sympathetic nervous system; laser-Doppler flowmetry