Yi Ma; Li-Ming Zhu; Wen-Ling Liu; Yu-Juan Yin; Xiao Chun Peng & Ming-Ming Zhu

To investigate changes of MMP-9 in the rat spleen and hypoxia-induced microvascular basement membrane under high altitude hypoxia. Thirty male specific pathogen-free Sprague Dawley rats were randomly divided into control and hypoxia groups, with 15 rats in each group. The rats in the control group were placed in Dingxi City, Gansu Province (2080 m above sea level) for 30 days. Rats in the hypoxia group were raised in a hypoxic environment in Maduo County, Qinghai Province (4300 m above sea level), for 30 days to establish a hypoxic rat model. Routine blood tests, MMP-9 mRNA, MMP-9 protein, and the spleen microvascular basement membrane were detected. (1) Compared with the control group, the red blood cell count, hemoglobin, and hematocrit levels of the rats in the hypoxia group were all increased; thus, a hypoxia model was successfully established. (2) Compared with the control group, the expression of MMP-9 mRNA and protein was significantly higher in the spleen of rats in the hypoxic group, and the difference was statistically significant (P <0.05). (3) Compared with the control group, the blood vessel basement membrane in the spleen of the hypoxia group was degraded. Under natural low air pressure and high altitude conditions, the expression of MMP-9 in rat spleen tissue increases and participates in the degradation of the microvascular basement membrane.

KEY WORDS: Hypoxia; Spleen; Basement membrane; MMP-9.

MA, Y.; ZHU, L. M.; LIU, W. L.; YIN, Y. J.; PENG, X. C. & ZHU, M. M. The role of MMP-9 in regulating degradation of the splenic microvascular basement membrane induced by high altitude hypoxia. Int. J. Morphol., 41(4):1152-1157, 2023.