Influence of physiological conditions on laser damage thresholds for blood, heart, and liver cells

✍ Scribed by Dmitri O. Lapotko; Ekaterina Y. Lukianova

• Publisher: John Wiley and Sons
• Year: 2005
• Tongue: English
• Weight: 143 KB
• Volume: 36
• Category: Article
• ISSN: 0196-8092
• DOI: 10.1002/lsm.20113

✦ Synopsis

Background and Objectives: Damage to blood and other tissues during laser interventions depends mainly upon absorption of laser radiation by cells. The objective of this work was to evaluate the influence tissue-specific physiological factors on photo-damage thresholds of individual cells: Red blood cells (blood), hepatocytes (liver), and miocytes (heart). Study Design/Materials and Methods: Laser-induced damage to individual cells was detected and studied with Laser Load Test (LLT). Probability and thresholds of RBC damage after one laser pulse (532 nm, 10 nanoseconds) were obtained experimentally as functions of physiological conditions. Using in vitro models, we have studied influence of the oxygen level, pH, temperature, and cell heterogeneity on RBC, the inhibition of metabolic activity on miocytes and drug toxicity on hepatocytes. Results: Single laser pulse induced cell lyses through a vapor bubble. The decrease of the O 2 level and temperature caused increase of damage thresholds at 532 nm. Deviation of the pH level from neutral to any side caused also the increase of the damage threshold. Inhibition of metabolism of miocytes and toxic damage to hepatocytes also resulted in the increase of the damage threshold. Conclusions: Resistance of various tissues at cell level against photo-damage significantly depends on physiological properties of cells. A general rule for such dependence is that the better the cell state the lower its threshold for laser-damage.