Sokolnicki Lynn A, Khosla Sundeep, Charkoudian Nisha
Department of Physiology and Biomedical Engineering, JO 4-184W, Mayo Clinic College of Medicine, Rochester, MN 55901, USA.
Am J Physiol Endocrinol Metab. 2007 Nov;293(5):E1426-9. doi: 10.1152/ajpendo.00535.2007. Epub 2007 Sep 25.
Microvascular vasodilation in humans can become impaired with age, leading to cardiovascular diseases ranging from mild to life-threatening. Reproductive hormones may confer some protection on the vascular system in women; however, it is unclear whether the same is true in men. Our goal was to evaluate the impact of four hormonal conditions (testosterone only, estradiol only, testosterone and estradiol, no testosterone and no estradiol) on microvascular vasodilator responsiveness in the skin of older men. We hypothesized that in older healthy men estradiol promotes cutaneous microvascular dilation during local warming of the skin and that testosterone inhibits this dilation. We measured skin blood flow using laser Doppler flowmetry during 35 min of cutaneous local warming to 42 degrees C in 52 healthy men (average age 67 +/- 1 yr). Subjects were randomized to one of the four hormonal conditions and were studied before and after hormone treatments. The endothelium-dependent vasodilator response to local warming was not different among groups either before or after hormone treatment. For example, with testosterone-only treatment this vasodilator response was 220 +/- 13 AU, and with estrogen only the response averaged 246 +/- 12 AU (P > 0.05). We conclude that, within the doses employed in the present study, testosterone and estradiol did not consistently alter cutaneous vasodilator responsiveness in healthy older men.
随着年龄增长，人类微血管舒张功能可能受损，从而引发从轻度到危及生命的心血管疾病。生殖激素或许能为女性的血管系统提供一定保护；然而，男性是否如此尚不清楚。我们的目标是评估四种激素状态（仅睾酮、仅雌二醇、睾酮与雌二醇、无睾酮且无雌二醇）对老年男性皮肤微血管舒张反应性的影响。我们假设，在老年健康男性中，雌二醇在皮肤局部升温时会促进皮肤微血管扩张，而睾酮会抑制这种扩张。我们在52名健康男性（平均年龄67±1岁）皮肤局部升温至42摄氏度的35分钟内，使用激光多普勒血流仪测量了皮肤血流量。受试者被随机分配到四种激素状态之一，并在激素治疗前后接受研究。激素治疗前后，各组对局部升温的内皮依赖性血管舒张反应并无差异。例如，仅接受睾酮治疗时，这种血管舒张反应为220±13 AU，仅接受雌激素治疗时，反应平均为246±12 AU（P>0.05）。我们得出结论，在本研究使用的剂量范围内，睾酮和雌二醇并未持续改变健康老年男性的皮肤血管舒张反应性。
