During normal pregnancy, and especially in the third trimester, both uterine blood flow and prostacyclin production by ovine uterine arteries are dramatically increased. We sought to determine if this is due, in part, to an increase in cyclooxygenase (COX) expression in the uterine artery endothelium. In this study we compared COX expression in uterine artery endothelium from nonpregnant and third-trimester pregnant (110-142 days' gestation) ewes. COX-2 expression was not detectable by Western blotting in uterine artery endothelium or vascular smooth muscle (VSM). In contrast, COX-1 expression was clearly observed in uterine artery. Immunohistochemical localization of COX-1 was endothelium > VSM, with both cell types showing an increase in COX-1 during the third trimester of pregnancy. COX-1 protein and messenger RNA (mRNA) levels were also detectable in collagenase dispersed endothelial cells, with expression of COX-1 in uterine artery endothelial cells dramatically increased during the third trimester of pregnancy at both the level of protein (346.4 +/- 28% of nonpregnant controls, P < 0.0005) and mRNA (51.04 +/- 7.98-fold of nonpregnant controls, P < 0.001). We conclude that the pregnancy-induced increases in prostacyclin production by uterine arteries is largely due to a dramatic increase in expression of COX-1 mRNA and associated protein predominantly occurring in the uterine artery endothelium and, to a lesser extent, in the VSM.

Uterine artery endothelial production of the potent vasodilator, prostacyclin, is greater in pregnant versus nonpregnant sheep and in whole uterine artery from intact versus ovariectomized ewes. We hypothesized that uterine artery cyclooxygenase (COX)-1 and/or COX-2 expression would be elevated during pregnancy (high estrogen and progesterone) and the follicular phase of the ovarian cycle (high estrogen/low progesterone) as compared to that in luteal phase (low estrogen/high progesterone) or in ovariectomized (low estrogen and progesterone) ewes. Uterine and systemic (omental) arteries were obtained from nonpregnant luteal-phase (LUT; n = 10), follicular-phase (FOL; n = 11), and ovariectomized (OVEX; n = 10) sheep, as well as from pregnant sheep (110-130 days gestation; term = 145 +/- 3 days; n = 12). Endothelial and vascular smooth muscle (VSM) COX-1 protein levels and uterine artery endothelial cell COX-1 mRNA levels were compared. Using immunohistochemistry and Western analysis, the primary location of COX-1 protein was the endothelium; that is, we observed 2.2-fold higher COX-1 protein levels in intact versus endothelium-denuded uterine artery and a 6.1-fold higher expression in the endothelium versus VSM (P < 0.05). COX-2 protein expression was not detectable in either uterine artery endothelium or VSM. COX-1 protein levels were observed to be higher (1.5-fold those of LUT) in uterine artery endothelium from FOL versus either OVEX or LUT nonpregnant ewes (P < 0.05), with substantially higher COX-1 levels seen in pregnancy (4.8-fold those of LUT). Increases in uterine artery endothelial COX-1 protein were highly correlated to increases in the level of COX-1 mRNA (r(2) = 0.66; P < 0.01) for all treatment groups (n = 6-8 per group), suggesting that increased COX-1 protein levels are regulated at the level of increased COX-1 mRNA. No change in COX-1 expression was observed between groups in a systemic (omental) artery. In conclusion, COX-1 expression is specifically up-regulated in the uterine artery endothelium during high uterine blood flow states such as the follicular phase and, in particular, pregnancy.

Although dependence on afferent synaptic activity has been shown for central neurons in every sensory system, the mechanisms of afferent maintenance of target sensory neurons are not understood. Neurons in the cochlear nucleus (CN) require afferent activity for maintenance and survival. One of the earliest changes seen after activity deprivation is an increase in intracellular calcium that leads to the death of 30% of the neuronal population. Sixty minutes after deafferentation, the surviving neurons show increased phosphorylation of the transcription factor calcium/cAMP response element-binding protein (CREB). CREB phosphorylation in activity-deprived CN neurons is dependent on increased intracellular calcium resulting from influx through AMPA receptors and is mediated by calcium/calmodulin-dependent kinases and protein kinase A. We conclude that in CN neurons, the deafferentation-induced increase in calcium activates at least two kinase pathways that phosphorylate CREB in surviving neurons. We hypothesize that this phosphorylation results in the transcription of genes containing the calcium/cAMP response element within their promoter regions, and these genes code for proteins that allow the neurons to compensate for their hypercalcemic, activity-deprived state.

Objective To determine if there are differences in maternal and fetal characteristics in pregnancies complicated by preterm versus term preeclampsia. Methods Using our electronic database we identified 143 women who met the ACOG criteria for preeclampsia between January 1995 and August 2003. We collected data on age, weight, height, smoking status, maternal serum biochemical markers and newborn data. We compared the group delivering preterm (<37 weeks) with those delivering at term (≥37 weeks). Analyses were based on ANOVA, Wilcoxon Rank Sum tests and chi-square tests. Statistical significance was determined based on alpha = .05. Data are expressed as mean ± s.d. unless otherwise indicated. Results Eighty women delivered preterm and 63 delivered at term. Women who delivered preterm with preeclampsia were younger (age 24.4 ± 4.9 years vs 27.7 ± 6.0 yrs, P<0.001), lighter (BMI 25.8 ± 5.6 vs 28.9 ± 7.3 kg/m2, P=0.01) and were more likely to smoke cigarettes (28% vs 9%, P=0.008) than those delivering at term with preeclampsia. Maternal serum liver enzyme concentrations were significantly greater in the preterm group (peak AST 38 vs 30 U/L, P=0.006), (peak ALT 31 vs 23 U/L, P=0.001). Newborn birth weight percentile (gestational age specific) was significantly lower for preterm preeclampsia (25th ±29 vs 47th ±32 percentile, P<0.001). We found no significant differences in maternal platelet count nadir, peak uric acid concentration, or newborn gender between groups. Conclusions Differences exist in maternal and fetal characteristics between women who develop preterm preeclampsia and those who develop preeclampsia at term. These data support the hypothesis that multiple preeclamptic phenotypes exist.

No abstract

Prostaglandin-endoperoxide synthase (PTGS) (also known as cyclooxygenase) converts arachidonic acid into several prostaglandins, many of which have roles in vasodilation and vasoconstriction under normal and pathological conditions. There are two isoforms of PTGS: PTGS-1 and PTGS-2; PTGS-1 is constitutively expressed in many tissues and is believed to be involved in the homeostatic maintenance of the body. In contrast, PTGS-2 is believed to have a "differentiative" role in the cells and is highly inducible during inflammation and in response to lipopolysaccharide (LPS). Endothelial cells as well as vascular smooth muscle cells can be a source of PTGS within the artery. The objective of this study was to determine the cell population(s) in uterine arteries that respond to LPS with an increase in PTGS-2 protein expression. Uterine arteries collected from ewes during the follicular (Day 0, Day 0 = estrus, n = 4) or luteal (Day 10, n = 4) phase were treated in vitro with LPS as intact artery segments, cut-open artery segments, or cut-open and denuded (endothelial cells absent) artery segments. After 24 h of LPS treatment, intact, cut-open, and denuded uterine artery segments were collected into homogenization buffer for determination of PTGS-2 protein levels by Western blot analysis. The culture medium was collected and used for detection of 6-keto-prostaglandin F(1alpha) (6-keto-PGF(1alpha)), the stable metabolite of prostacyclin, using an enzyme immunoassay. In addition, the location of PTGS-2 after LPS treatment was analyzed by immunohistochemistry in intact artery segments. Denuded arteries (endothelium absent) did not show increases in PTGS-2 protein in the homogenates or 6-keto-PGF(1alpha) in the culture medium after LPS exposure. In contrast, cut uterine arteries responded to LPS stimulation with a significant increase in PTGS-2 protein in homogenates and 6-keto-PGF(1alpha) in culture medium. Immunohistochemical staining for PTGS-2 was associated with both endothelial cells and vascular smooth muscle cells. These results suggest that while both endothelial cells and vascular smooth muscle cells are associated with PTGS-2, after LPS exposure it is the endothelial cells that are essential in uterine artery increases in PTGS-2 and prostacyclin in response to LPS stimulation.

During normal pregnancy, and especially in the third trimester, both uterine blood flow and prostacyclin production by ovine uterine arteries are dramatically increased. We sought to determine if this is due, in part, to an increase in cyclooxygenase (COX) expression in the uterine artery endothelium. In this study we compared COX expression in uterine artery endothelium from nonpregnant and third-trimester pregnant (110-142 days' gestation) ewes. COX-2 expression was not detectable by Western blotting in uterine artery endothelium or vascular smooth muscle (VSM). In contrast, COX-1 expression was clearly observed in uterine artery. Immunohistochemical localization of COX-1 was endothelium > VSM, with both cell types showing an increase in COX-1 during the third trimester of pregnancy. COX-1 protein and messenger RNA (mRNA) levels were also detectable in collagenase dispersed endothelial cells, with expression of COX-1 in uterine artery endothelial cells dramatically increased during the third trimester of pregnancy at both the level of protein (346.4 +/- 28% of nonpregnant controls, P < 0.0005) and mRNA (51.04 +/- 7.98-fold of nonpregnant controls, P < 0.001). We conclude that the pregnancy-induced increases in prostacyclin production by uterine arteries is largely due to a dramatic increase in expression of COX-1 mRNA and associated protein predominantly occurring in the uterine artery endothelium and, to a lesser extent, in the VSM.

Neurons of the chick cochlear nucleus, nucleus magnocellularis (NM), require eighth nerve activation of metabotropic glutamate receptors (mGluRs) for maintenance of intracellular calcium homeostasis. Interrupting this activation results in an increase in intracellular calcium concentration ([Ca(2+)](i)) followed by cell atrophy, degeneration, and death of many neurons. Although these phenomena are well characterized in late embryonic and posthatch chicks, little is known about the role of mGluRs and calcium homeostasis during the development of synaptic activity in NM. Using Fura-2 imaging, fluorescent immunohistochemistry, and Western immunoblotting, we investigated (1) the expression and function of group I mGluRs and their role in calcium regulation during development of NM, and (2) the expression of two other key molecules involved in regulating neuronal [Ca(2+)](i) : inositol trisphosphate receptors (IP(3)Rs) and sarcoplasmic/endoplasmic reticulum calcium ATPases (SERCAs). Confocal imaging of Fluo-3-labeled NM was used to investigate the kinetics of global NM neuron calcium signals. Measurements were made at four ages that extend from before synaptic function begins in NM, through functional onset, to mature patterns of spontaneous activity, namely, embryonic days (E) 10, 13, 15, and 18. mGluR5, mGluR1, and SERCA expression peaked at E13 and then decreased with age. IP(3)R expression increased to peak at E18. [Ca(2+)](i) response to mGluR activation increased with age. The rise time of [Ca(2+)](i) signals in NM neurons did not change with development, but E13 neurons were slower to reestablish baseline [Ca(2+)](i). These results suggest that the mGluR-mediated calcium homeostasis of NM neurons develops in parallel with synaptic activity and appears to be refined with increasing synaptic activity.