LAUSR

Cumulating evidence demonstrated that chronic intermittent hypobaric hypoxia (CIHH) had beneficial effects on the body. The present study investigated the role of perivascular adipose tissue (PVAT) in ameliorating effect of CIHH on vascular reactivity by adiponectin in mesenteric artery of metabolic syndrome (MS) rats. Main methods: Six-week-old male Sprague-Dawley rats were randomly divided into four groups: control (CON), MS model, CIHH treatment, and MS plus CIHH treatment (MS+CIHH) group. The size of adipocytes in PVAT was measured by scanning electron microscopy. Serum adiponectin was measured. The microvessel recording technique was used to observe the effect of CIHH on contraction and relaxation in mesenteric artery rings. Also, the expression of interleukin-1β, tumor necrosis factor-α, adiponectin, AdipoR1, AdipoR2, APPL1, and endothelial nitric oxide synthase (eNOS) were assayed by Western blotting. Key findings: In MS rats, adipocyte size increased, serum adiponectin decreased, contraction reaction increased while relaxation reaction decreased, and the expression of pro-inflammatory cytokines was upregulated, while adiponectin was downregulated in PVAT, and the expression of AdipoR1, AdipoR2, APPL and phosphorylated-eNOS was downregulated in mesenteric artery. All aforementioned abnormalities of MS were ameliorated in MS+CIHH rats. We concluded that CIHH treatment improves vascular reactivity through upregulating adiponectin expression and downregulating pro-inflammatory cytokines expression of PVAT in MS rats.