Diurnal and long-term variations of lymph capillary pressure in health

Abstract

The variability of pressure in the cutaneous lymph capillaries on the forefoot was determined in 2 groups of healthy volunteers. In group A, including 12 subjects (8 men, 4 women; mean age 28 years, range 22 to 37 years) measurements were performed in the morning and late afternoon of the same day. In group B (12 subjects, 5 women, 7 men; mean age 53 years, range 23 to 72 years) measurements of lymph capillary pressure were repeated within an interval of 7 weeks. The superficial microlymphatics were visualized by intravital fluorescence microlymphography, cannulated with glass micropipettes, and the lymph capillary pressure was measured using a servo-nulling pressure system. The lymph capillary pressure measured in the morning (mean 7.5±4.4 mm Hg; range −4 to 16 mm Hg) did not differ (p>0.05) from the pressure in the late afternoon (mean value 5.6±3.4 mm Hg; range −1 to 13 mm Hg). In group B initial lymph capillary pressure (mean 3.9±2.9 mm Hg, range −1.1 to 9.7 mm Hg) was not different (p>0.05) compared to the pressure after 7 weeks (2.9±2.7 mm Hg; range −1.0 to 6.8 mm Hg). In conclusion, lymph capillary pressure in healthy subjects does not exhibit significant changes during the daytime and the long-term reproducibility is good.