Changes in mesenteric lymph microcirculation in rats suffering from severe heatstroke / 解放军医学杂志

ABSTRACT

Objective To observe the dynamic changes in mesenteric lymph microcirculation and its kinetics in rats suffering from severe heatstroke (SHS), and to explore the role of mesenteric lymph in the pathogenesis of SHS. Methods SHS rat models were reproduced in an incubator with high temperature and high humidity. The vital signs and the time of onset of SHS in rats were recorded continuously during the process of heat stress. Parameters of mesenteric lymph microcirculation including Index-I, Index-II, L.D-Index, and intra-lymphatic pressure before heat exposure, 60min after heat exposure, and onset of SHS were collected and analyzed. Mesenteric lymph was collected at 30-min interval, and its volume of production was measured dynamically. Results Rat SHS model was reproduced successfully. After exposure to the environment with high temperature and high humidity, the core temperatures of the rats raised to 42°C at the time point of 60min, and HS onset occurred at about 77min. Mesenteric lymph-vessel contraction indices including Index-I, Index-II, L.D-Index, lymph-vessel pressure and mesenteric lymph flow decreased significantly at the time point of 60min (P<0.05). However, all the above parameters increased at the time point of SHS onset (P<0.05), but had not yet reached the normal levels before hyperthermia and high humidity exposure (P<0.05). Conclusion Changes of mesenteric lymph microcirculation in rats with SHS shows a dynamical regularity, which may take part in the pathogenesis of SHS.