Volume 29, Issue 3
DOI: 10.24205/03276716.2020.711
Effects of inflammatory stimulation during pregnancy on mesenteric vascular function of offspring rats
Abstract
To evaluate the effects of inflammatory stimulation during pregnancy on the mesenteric vascular function of offspring rats. Twenty-four Sprague-Dawley pregnant rats were randomly divided into a control group and a lipopolysaccharide (LPS) stimulation group that were intraperitoneally injected with normal saline and LPS (0.79 mg/kg) on the 8th, 10th and 12th days of pregnancy respectively. At 8 weeks of age, 12 male pups were randomly selected from each group for subsequent experiments. Their blood pressures at 9, 11, 13 and 15 weeks of age were measured noninvasively at the tail. The responses of mesenteric tertiary blood vessels to 10-10~10-5 mol/L angiotensin II (AngII) were observed. AT1R expression in mesenteric vessels was detected by Western blotting. The systolic blood pressure of the LPS stimulation group was significantly higher than that of the control group at 9, 11, 13 and 15 W (P<0.05). The maximum contractile response of the mesenteric artery induced by AngII in the LPS group exceeded that of the control group [(8.49 ± 0.32) vs. (3.47 ± 0.29) mN, P<0.05]. When the concentrations of AngII were 10-7, 10-6 and 10-5 mmol/L, the contractile responses of the mesenteric artery in the LPS group all exceeded those of the control group [(5.99 ± 0.48) vs. (2.21 ± 0.19), (7.10 ± 0.11) vs. (3.02 ± 0.43) and (8.51 ± 0.39) vs. (3.49 ± 0.29) mN respectively, P<0.01]. After pre-incubation with losartan for 30 min, the contractile response to AngII of each group was significantly inhibited, without a significant difference. The expression of AT1R protein in the mesenteric artery of the LPS group surpassed that of the control group [(1.51 ± 0.10) vs. (1.01 ± 0.09), P<0.05]. Exposure to LPS during pregnancy leads to abnormal AngII-mediated vasoconstriction and increases the vascular resistance in offspring rats, which may be an important reason for the elevation of blood pressure.
Keywords
pregnancy; inflammatory stimulation; lipopolysaccharide; mesentery; vascular function