Comparison of lymph and blood flow in microvessels: coherent optical measurements

Abstract

In the present study the characteristics of blood and lymph microcirculation are investigated. The microcirculation was studied on small intestine mesentery in norm and during N<SUP>G</SUP>-nitro-L-arginine (L- NNA) application. The direct measurement of lymph flow velocity (parameter V) in individual microvessels was based on the technique of light intravital videomicroscopy. The first spectral moments of Doppler signal characterizing the mean velocities of lymph and blood flow in microvessels (parameters M<SUB>1L</SUB> and M<SUB>1B</SUB>) were measured by speckle- interferometrical method. Simultaneously, diameters of blood and lymph microvessels as well as parameters of phasic contractions and valve function of lymphatics were registered. The mean diamters of investigated lymphatics and venules were 170±20 &#956;m and 8±0.5 &#956;m, correspondingly. In 24% of lymph microvessels phasic contractions were observed. The mean flow velocity in blood microvessels was 10 times more than the one in lymphatics. L-NNA application led to variable effects on diameter of lymphatics, increased the number of microvessels with phasic contractions and modified parameters of these contractions. The mean velocity of lymph flow (V) was increased. The mean value of M1<SUB>L</SUB> was not changed; the M1<SUB>L</SUB> maximum in 75% of the lymphatics was increased. In 88% of venules M1<SUB>B</SUB> was decreased on 25±7%.