ANP Improves The Water And Salt Metabolism During Cooling Treatment For Exertional Heat Stroke

Corresponding author: Qingwen Peng. The pathogenesis of exertional heat stroke is related to water and salt metabolism disorder, but the effect of cooling treatment on serum atrial natriuretic peptide(ANP) and the mechanism of regulating water and salt metabolism is still unclear. PURPOSE: To determine the changes of serum ANP and its effects on water and salt metabolism in exertional heat stroke rats during cooling treatment. METHODS: In this subject, there are four groups of male SD rats, including the Normal Control group(NC n = 8), the Occurring group of EHS(OEHS,n = 9), the natural Rest group after EHS(REHS n = 9), and the Cooling treatment group after EHS(CEHS,n = 8). In addition to the NC group, the other three groups of rats exercised to exhaustion in hot and humid conditions of 36 °C and 75%RH, and increased their rectal temperature to about 42 °C to create the EHS rat model. The method of cooling treatment for ESH rats was to immerse them in cold water for 5 minutes at 19 °C. The tester took the rats blood and determined the level of serum ANP by ELISA. The ANP kit for rats is from Enzolife Company of the United States. The Mann Whitney U test in nonparametric test is adopted for statistical analysis. RESULTS: At the beginning of exertional heat stroke, the serum ANP regulating water and salt metabolism decreased significantly (OEHS vs. NC) (ANP: 73.39 ± 20.61 vs. 122.66 ± 12.52 pg/ml, p < 0.01). After cooling treatment for 5 min, there was no significant change in serum ANP(CEHS vs. OEHS or REHS) (ANP: 88.62 ± 26.76 vs. 73.39 ± 20.61 or 101.97 ± 17.97 pg/ml, p > 0.05). At the same time, ANP in the REHS group increased significantly after 5 minutes rest(REHS vs. OEHS) (ANP: 101.97 ± 17.97 vs. 73.39 ± 20.61, p < 0.01). CONCLUSION: In the case of exertional heat stroke, the serum ANP decreases abnormally, which proves that ANP pathway is used to combat dehydration and desalination caused by high temperature exercise. When the serum ANP in the rest group rose rapidly, cooling treatment has no significant effect on serum atrial natriuretic peptide, which indicates that cooling treatment can continuously regulate the dehydration and desalination of the body through the mechanism of ANP factor. The research has sponsored by the general fund project of Philosophy and Social Science Planning Project in Anhui Province in 2022(Project Number: AHSKY2022D184). The research has sponsored by the general fund project of Philosophy and Social Science Planning Project in Anhui Province in 2022(Project Number: AHSKY2022D184).