Aberrant Water Structure Dynamics in B16 Melanoma-Bearing Mice by Time Domain Refractometry Analysis

Simple Summary Living bodies comprise approximately 55-75% water to maintain homeostasis. However, little is known about the differences in in vivo water molecule dynamics (water structure dynamics; WSD) under physiological and pathophysiological statuses. Here, we examined the WSD of ex vivo samples in tumor-bearing mice versus healthy mice by dielectric spectroscopy using time domain reflectometry. Tumor tissues, from early after engrafting, exhibited remarkable features of WSD close to pure water, different from the other organs of tumor-bearing and healthy mice. Further, certain organs in tumor-bearing mice temporally revealed different WSD features compared to those in healthy mice. Conclusively, tumor-bearing mice revealed aberrant WSD, unlike healthy mice. Thus, dielectric spectroscopy in terms of WSD may provide novel pathophysiological perspectives in living organisms.Abstract Living bodies comprise approximately 55-75% water to maintain homeostasis. However, little is known about the comprehensive differences in in vivo water molecule dynamics (water structure dynamics; WSD) between physiological and pathophysiological statuses. Here, we examined the WSD of ex vivo tumor tissues and organs from tumor-bearing mice with engrafted mouse malignant melanoma cells (B16-F10) in the right flanks to compare with those in healthy mice, using time domain reflectometry of dielectric spectroscopy at days 9, 11, and 14 after engrafting. The relaxation parameters of relaxation time (& tau;), relaxation time distribution parameter (& beta;), and relaxation strength ( increment & epsilon;) were measured on tumor tissues and lung, liver, kidney, and skin tissues. Immediately afterward, the water contents (%) in the tumor and the other organs were calculated by measuring their weights before and after freeze-drying. Each parameter of the tumor was compared to that of pooled values of other organs in tumor-bearing (TO) and healthy mice (HO). The tumor water content temporarily increased compared to that of HO at day 11; the tumor volume was also prone to increase. In contrast, tumor tissues exhibited significantly higher values of & beta; close to 1 of ultrapure water and increment & epsilon; compared to TO and HO at all times. Moreover, & beta; in the viscera of TO was prone to increase compared to that of HO with significantly higher levels at day 11. Conclusively, tumor-bearing mice exhibited systemically aberrant WSD, unlike healthy mice. Thus, dielectric spectroscopy in terms of WSD may provide novel pathophysiological perspectives in tumor-bearing living bodies.