The present study tested the hypothesis that angiotensin II plays a role in the regulation of placental vascular tone, which contributes to hypertension in preeclampsia. Functional and molecular assays were performed in large and micro placental and non-placental vessels from humans and animals. In human placental vessels, angiotensin II induced vasoconstrictions in 78.7% vessels in 155 tests, as referenced to KCl-induced contractions. In contrast, phenylephrine only produced contractions in 3.0% of 133 tests. In non-placental vessels, phenylephrine induced contractions in 76.0% of 67 tests, whereas angiotensin II failed to produce contractions in 75 tests. Similar results were obtained in animal placental and non-placental vessels. Compared with non-placental vessels, angiotensin II receptors and β -adrenoceptors were significantly increased in placental vessels. Compared to the vessels from normal pregnancy, angiotensin II-induced vasoconstrictions were significantly reduced in preeclamptic placentas, which was associated with a decrease in angiotensin II receptors. In addition, angiotensin II and angiotensin converting enzyme in the maternal-placenta circulation in preeclampsia were increased, whereas angiotensin I and angiotensin1-7 concentrations were unchanged. The study demonstrates a selective effect of angiotensin II in maintaining placental vessel tension, which may play an important role in development of hypertension in preeclampsia.

Overnutrition during pregnancy could increase risks of cardiovascular diseases in late life. This study investigated whether and how reactive oxygen species (ROS) may influence functions of large-conductance Ca2+-activated K+ channels (BKCa) in the offspring exposed to prenatal high sucrose (HS). We found that prenatal HS diets significantly increased phenylephrine (PE)-induced vessel contractions in mesenteric arteries of the adult offspring. Pretreatment with iberiotoxin (BKCa blocker, IBTX) significantly increased PE-mediated vascular contractions in the control, not in the HS group. Electrophysiological studies demonstrated that BKCa current density and single-channel current were reduced in the vascular smooth muscle cells (VSMCs) of the HS offspring. The expression of BKCa alpha, beta1 subunits in mesenteric arteries was decreased in the HS offspring, indicating that both activity and number of BKCa channels in HS offspring were reduced. Superoxide production and NADPH oxidase (NOX)4 of the HS offspring were elevated. Following inhibiting NOX by apocynin, vasoconstriction in the HS offspring was weakened and the reduced currents in the VSMCs were improved with altered protein kinase B (AKT) pathway. The results suggested that NOX4-derived ROS might inhibit the offspring vascular BKCa channel activity via AKT pathway.

Both prenatal and prenatal-plus-postnatal high sucrose exposure substantially affect biological functions related to insulin homeostasis. IRS-1(S612) protein phosphorylation appears to be a part of the molecular mechanism underlying these effects. These results add to the understanding of how high sucrose intake contributes to insulin resistance and diabetes pathogenesis and how postnatal nutrition and lifestyle may mitigate detrimental prenatal exposures.

Rhodiola as one of traditional medicines has been used for clinical treatments due to its strong antioxidant properties. Phytochemical analysis revealed the presence of flavonoids, phenylpropanoids, phenylethanol/benzyl alcohol derivatives, cyanogenic glycosides and terpenoids. The bioactive compounds had been demonstrated to be effective at scavenging reactive oxygen species (ROS). The structures contain phenolic hydroxyl groups and unsaturated bonds. This article reviews antioxidant capacities of the extracts and bioactive components derived from Rhodiola plants. As the major pharmacological ingredient, salidroside is rigorously investigated and used in scientific researches and clinical practices. Accumulated evidences indicated that extracts of Rhodiola plants or salidroside could be able to reverse DNA damage and alter expression of cytokines and antioxidative enzymes induced by ROS. The underlying mechanisms for the antioxidative effects of the herb have been investigated in the last two decades. We summarize the possible effects and acting pathways for the herb involved in several chronic diseases in cardiovascular, respiratory, and nervous systems, as well as potential epigenetic influences. The information generated from experimental and clinical studies offered valuable insights for further investigations of medical potentials of Rhodiola plants.

Background/Aims: Chronic hypoxia in utero could impair vascular functions in the offspring, underlying mechanisms are unclear. This study investigated functional alteration in large-conductance Ca²⁺-activated K⁺ (BK) channels in offspring mesenteric arteries following prenatal hypoxia. Methods: Pregnant rats were exposed to normoxic control (21% O₂, Con) or hypoxic (10.5% O₂, Hy) conditions from gestational day 5 to 21, their 7-month-old adult male offspring were tested for blood pressure, vascular BK channel functions and expression using patch clamp and wire myograh technique, western blotting, and qRT-PCR. Results: Prenatal hypoxia increased pressor responses and vasoconstrictions to phenylephrine in the offspring. Whole-cell currents density of BK channels and amplitude of spontaneous transient outward currents (STOCs), not the frequency, were significantly reduced in Hy vascular myocytes. The sensitivity of BK channels to voltage, Ca²⁺, and tamoxifen were reduced in Hy myocytes, whereas the number of channels per patch and the single-channel conductance were unchanged. Prenatal hypoxia impaired NS1102- and tamoxifen-mediated relaxation in mesenteric arteries precontracted with phenylephrine in the presence of N^ω-nitro-L-arginine methyl ester. The mRNA and protein expression of BK channel β1, not the α-subunit, was decreased in Hy mesenteric arteries. Conclusions: Impaired BK channel β1-subunits in vascular smooth muscle cells contributed to vascular dysfunction in the offspring exposed to prenatal hypoxia.