Fig. 2.

IAV infection causes vascular dysfunction in pregnant mice. Vascular reactivity was measured in isolated maternal thoracic aortic rings of pregnant and nonpregnant mice inoculated with PBS or Hk-x31 (X-31; 10⁴ PFU) for assessment at 3 dpi (D3) and 6 dpi (D6). (A) Endothelium-dependent vasodilation to ACh. (B) Endothelium-independent vasodilation to SNP. (C) Endothelium-dependent (ACh) and independent (SNP) vasodilation was also performed in nonpregnant mice at 3 dpi. Vascular relaxation is calculated as a percentage of preconstriction to U-46619. Data are represented as mean ± SEM (pregnant PBS, n = 6 to 8; pregnant X-31, n = 6 to 8; nonpregnant PBS, n = 6 of at least two independent experiments). Statistical analysis was conducted by using a two-way ANOVA followed by Holm’s Sidak post hoc multiple comparison. *P < 0.05; ^#P < 0.0001.