Stress-induced changes in lymph microcirculation

In the present study some characteristics of lymph microcirculation in mesentery of intact and stressed rats were investigated. The stress was modelled by simultaneous action of rigid immobilization and interrupting sound during 2 h. The direct observation of lymph circulation in microvessels was based on the light intravital videomicroscopy technique. The diameters of microvessels as well as parameters of phasic contractions and valve function of lymphatics were registered. After stress the mean diameter of lymphatic vessels was increased by 13%. The number of microvessels with phasic contractions raised by 20%. The amplitude and frequency of phasic contractions decreased by 31 and 39%, respectively. The percentage of microvessels with lymph flow comprised 86% in control and 93% in stressed animals. The mean velocity of lymph flow increased by 61 mum/s whereas the rate of valve work was not modified after stress.