Reductions of Circulating Nitric Oxide are Followed by Hypertension during Pregnancy and Increased Activity of Matrix Metalloproteinases-2 and -9 in Rats

Figure 1. Systolic blood pressure measurements (A) and NO bioavailability in plasma (B) of virgin rats and Early, middle (Mid) and Late-pregnant rats treated with saline or L-NAME. Values are represented as mean ± SEM. In the panel A, *P < 0.05 versus baseline (BL) of each group and #P < 0.05 versus respective day of each group treated with saline. In the panel B, *P < 0.05 versus Virgin group, #P < 0.05 versus respective Mid-Preg or Late-Preg groups, +P < 0.05 versus Early-Preg or Early-Preg+L-NAME groups, and ++P < 0.05 versus Mid-Preg or Mid-Preg+L-NAME groups.

Figure 2. Fetal and placental parameters: (A) Litter size, (B) Number of viable fetuses, (C) Number of reabsorptions, (D) Fetal weight and (E) Placental weight in Early, middle (Mid) and Late-pregnant rats treated with saline or L-NAME. Values are represented as mean ± SEM. #P < 0.05 versus respective saline-treated pregnant groups.

Figure 3. Oxidative stress of virgin rats and Early, middle (Mid) and Late-pregnant rats treated with saline or L-NAME. Values represent mean ± SEM. *P < 0.05 versus Virgin group, #P < 0.05 versus the Mid-Preg group, +P < 0.05 versus Early-Preg and Early-Preg+L-NAME groups, and ++P < 0.05 versus Mid-Preg and Mid-Preg+L-NAME groups.

Figure 4. Representative zymography gel from the plasma (A). Gelatinolytic activity of 92 KDa MMP-9 (B), 75 KDa MMP-2 (C), 72 KDa MMP-2 (D), 64 KDa MMP-2 was not detected (E) and total MMP-2 (F) in virgin rats and Early, middle (Mid) and Late-pregnant rats treated with saline or L-NAME. Values represent mean ± SEM. *P < 0.05 versus the Virgin group, #P < 0.05 versus the Late-Preg group.

Figure 5. Representative zymography gel from the uterus (A). Gelatinolytic activity of 92 KDa MMP-9 was only detected in Late-Perg+LNAME group (B), and, 75 KDa MMP-2 (C), 72 KDa MMP-2 (D), 64 KDa MMP-2 (E), and total MMP-2 (F) in virgin rats and Early, middle (Mid), and Late-pregnant rats treated with saline or L-NAME. Values represent mean ± SEM. *P < 0.05 versus Virgin group, #P < 0.05 versus respective Early-Preg, Mid-Preg and Late-Preg groups, +P < 0.05 versus Early-Preg group and ++P < 0.05 versus Mid-Preg or Mid-Preg+L-NAME groups.

Figure 6. Representative zymography gel from the placenta (A). Gelatinolytic activity of 92 KDa MMP-9 (B), 75 KDa MMP-2 (C), 72 KDa MMP-2 (D), 64 KDa MMP-2 (E) and total MMP-2 (F) in middle (Mid) and Late-pregnant rats treated with saline or L-NAME. Values represent mean ± SEM. #P < 0.05 versus respective saline-treated group, and +P < 0.05 versus respective Mid-Preg group, ++P < 0.05 versus respective Mid-Preg+L-NAME group for 64 KDa and total MMP-2 activities.

Figure 7. Representative zymography gel from the aorta (A). Gelatinolytic activity of 92 KDa MMP-9 was not detected (B), and, 75 KDa MMP-2 (C), 72 KDa MMP-2 (D), 64 KDa MMP-2 (E) and total MMP-2 (F) in virgin rats and Early, middle (Mid) and Late-pregnant rats treated with saline or L-NAME. Values represent mean ± SEM. *P < 0.05 versus the Virgin group, #P < 0.05 versus respective Early-Preg, Mid-Preg and Late-Preg groups, +P < 0.05 versus the respective Early-Preg group.