Amsterdam UMC location University of Amsterdam, Biomedical Engineering and Physics, Meibergdreef 9, Amsterdam, the Netherlands.
Amsterdam Cardiovascular Sciences, Microcirculation, Amsterdam, the Netherlands.
Lasers Med Sci. 2024 May 4;39(1):122. doi: 10.1007/s10103-024-04070-7.
Pulsed dye lasers are used effectively in the treatment of psoriasis with long remission time and limited side effects. It is, however, not completely understood which biological processes underlie its favorable outcome. Pulsed dye laser treatment at 585-595 nm targets hemoglobin in the blood, inducing local hyperthermia in surrounding blood vessels and adjacent tissues. While the impact of destructive temperatures on blood vessels has been well studied, the effects of lower temperatures on the function of several cell types within the blood vessel wall and its periphery are not known. The aim of our study is to assess the functionality of isolated blood vessels after exposure to moderate hyperthermia (45 to 60°C) by evaluating the function of endothelial cells, smooth muscle cells, and vascular nerves. We measured blood vessel functionality of rat mesenteric arteries (n=19) by measuring vascular contraction and relaxation before and after heating vessels in a wire myograph. To this end, we elicited vascular contraction by addition of either high potassium solution or the thromboxane analogue U46619 to stimulate smooth muscle cells, and electrical field stimulation (EFS) to stimulate nerves. For measurement of endothelium-dependent relaxation, we used methacholine. Each vessel was exposed to one temperature in the range of 45-60°C for 30 seconds and a relative change in functional response after hyperthermia was determined by comparison with the response per stimulus before heating. Non-linear regression was used to fit our dataset to obtain the temperature needed to reduce blood vessel function by 50% (Half maximal effective temperature, ET50). Our findings demonstrate a substantial decrease in relative functional response for all three cell types following exposure to 55°C-60°C. There was no significant difference between the ET50 values of the different cell types, which was between 55.9°C and 56.9°C (P>0.05). Our data show that blood vessel functionality decreases significantly when exposed to temperatures between 55°C-60°C for 30 seconds. The results show functionality of endothelial cells, smooth muscle cells, and vascular nerves is similarly impaired. These results help to understand the biological effects of hyperthermia and may aid in tailoring laser and light strategies for selective photothermolysis that contribute to disease modification of psoriasis after pulsed dye laser treatment.
脉冲染料激光在治疗银屑病方面效果显著，具有长时间的缓解期和有限的副作用。然而，其良好疗效的背后所涉及的生物学过程还不完全清楚。585-595nm 的脉冲染料激光治疗针对的是血液中的血红蛋白，会导致周围血管和相邻组织发生局部过热。虽然已经对破坏性温度对血管的影响进行了充分研究，但对于较低温度对血管壁及其周围的几种细胞类型功能的影响还知之甚少。我们的研究目的是通过评估内皮细胞、平滑肌细胞和血管神经的功能来评估中度过热（45 至 60°C）暴露后分离血管的功能。我们通过在电生理记录仪中加热血管前后测量大鼠肠系膜动脉（n=19）的血管收缩和舒张来测量血管功能。为此，我们通过加入高钾溶液或血栓烷类似物 U46619 刺激平滑肌细胞，以及电刺激（EFS）刺激神经来引起血管收缩。为了测量内皮依赖性舒张，我们使用了甲酰胆碱。每个血管都在 45-60°C 的温度范围内暴露 30 秒，并通过与加热前每个刺激的反应相比确定加热后功能反应的相对变化来确定功能变化。我们使用非线性回归来拟合数据集，以获得使血管功能降低 50%（半最大有效温度，ET50）所需的温度。我们的研究结果表明，所有三种细胞类型在暴露于 55°C-60°C 后，相对功能反应均显著下降。不同细胞类型的 ET50 值之间没有显著差异，介于 55.9°C 和 56.9°C 之间（P>0.05）。我们的数据表明，血管在 30 秒内暴露于 55°C-60°C 之间的温度时，其功能会显著降低。结果表明内皮细胞、平滑肌细胞和血管神经的功能同样受到损害。这些结果有助于了解过热的生物学效应，并可能有助于为脉冲染料激光治疗后银屑病的疾病修饰量身定制激光和光策略，以实现选择性光热解。
