Estrogen receptor alpha (ER alpha) and ER beta are members of the steroid nuclear receptor family that modulate gene transcription in an estrogen-dependent manner. ER mRNA and protein have been detected both peripherally and in the central nervous system, with most data having come from the rat. Here we report the development of an ER beta-selective antibody that cross-reacts with mouse, rat, and human ER beta protein and its use to determine the distribution of ER beta in the murine brain. Further, a previously characterized polyclonal antibody to ER alpha was used to compare the distribution of the two receptors in the first comprehensive description of ER distribution specifically in the mouse brain. ER beta immunoreactivity (ir) was primarily localized to cell nuclei within select regions of the brain, including the olfactory bulb, cerebral cortex, septum, preoptic area, bed nucleus of the stria terminalis, amygdala, paraventricular hypothalamic nucleus, thalamus, ventral tegmental area, substantia nigra, dorsal raphe, locus coeruleus, and cerebellum. Extranuclear-ir was detected in several areas, including fibers of the olfactory bulb, CA3 stratum lucidum, and CA1 stratum radiatum of the hippocampus and cerebellum. Although both receptors were generally expressed in a similar distribution through the brain, nuclear ER alpha-ir was the predominant subtype in the hippocampus, preoptic area, and most of the hypothalamus, whereas it was sparse or absent from the cerebral cortex and cerebellum. Collectively, these findings demonstrate the region-selective expression of ER beta and ER alpha in the adult ovariectomized mouse brain. These data provide an anatomical framework for understanding the mechanisms by which estrogen regulates specific neural systems in the mouse.

The expression and localization of glucose transporter isoforms play essential roles in the glucoregulatory activities of the hippocampus and ultimately contribute to cognitive status in physiological and pathophysiological settings. The recently identified glucose transporter GLUT8 is uniquely expressed in neuronal cell bodies in the rat hippocampus and therefore may contribute to hippocampal glucoregulatory activities. We show here that GLUT8 has a novel intracellular distribution in hippocampal neurons and is translocated to intracellular membranes following glucose challenge. Immunoblot analysis revealed that GLUT8 is expressed in high-density microsomes (HDM), suggesting that GLUT8 is associated with intracellular organelles under basal conditions. Immunogold electron microscopic analysis confirmed this observation, in that GLUT8 immunogold particles were associated with the rough endoplasmic reticulum (ER) and cytoplasm. Peripheral glucose administration produced a rapid twofold increase in GLUT8 levels in the HDM fraction while decreasing GLUT8 levels in low-density microsomes. Similarly, peripheral glucose administration significantly increased GLUT8 association with the rough ER in the hippocampus. Conversely, under hyperglycemic/insulinopenic conditions, namely, in streptozotocin (STZ) diabetes, hippocampal GLUT8 protein levels were decreased in the HDM fraction. These results demonstrate that GLUT8 undergoes rapid translocation to the rough ER in the rat hippocampus following peripheral glucose administration, trafficking that is impaired in STZ diabetes, suggesting that insulin serves as a stimulus for GLUT8 translocation in hippocampal neurons. Because glucose is liberated from oligosaccharides during N-linked glycosylation events in the rough ER, we propose that GLUT8 may serve to transport glucose out of the rough ER into the cytosol and in this manner contribute to glucose homeostasis in hippocampal neurons.

We describe the localization of the recently identified glucose transporter GLUTx1 and the regulation of GLUTx1 in the hippocampus of diabetic and control rats. GLUTx1 mRNA and protein exhibit a unique distribution when compared with other glucose transporter isoforms expressed in the rat hippocampus. In particular, GLUTx1 mRNA was detected in hippocampal pyramidal neurons and granule neurons of the dentate gyrus as well as in nonprincipal neurons. With immunohistochemistry, GLUTx1 protein expression is limited to neuronal cell bodies and the most proximal dendrites, unlike GLUT3 expression that is observed throughout the neuropil. Immunoblot analysis of hippocampal membrane fractions revealed that GLUTx1 protein expression is primarily localized to the intracellular compartment and exhibits limited association with the plasma membrane. In streptozotocin diabetic rats compared with vehicle-treated controls, quantitative autoradiography showed increased GLUTx1 mRNA levels in pyramidal neurons and granule neurons; up-regulation of GLUTx1 mRNA also was found in nonprincipal cells, as shown by single-cell emulsion autoradiography. In contrast, diabetic and control rats expressed similar levels of hippocampal GLUTx1 protein. These results indicate that GLUTx1 mRNA and protein have a unique expression pattern in rat hippocampus and suggest that streptozotocin diabetes increases steady-state mRNA levels in the absence of concomitant increases in GLUTx1 protein expression. T he family of facilitative glucose transporter (GLUT) proteins is responsible for the entry of glucose into cells throughout the periphery and the brain (1, 2). In the central nervous system (CNS), glucose transporters play an essential role in neuronal homeostasis, because glucose represents the primary energy source for the brain (3, 4). Metabolic disorders that disrupt glucose delivery or utilization in the CNS may adversely affect neuronal activity, particularly cognitive function. For example, glucose utilization is reduced in Alzheimer's disease (AD) (5), and the cognitive impairments associated with AD can be ameliorated to some extent by glucose administration (6) and insulin therapy (7). Similarly, diabetes mellitus (type 1 or insulindependent diabetes) is associated with cognitive impairments in humans and in animal models of hyperglycemia (8). Reductions in glucose transport in the CNS may be particularly endangering to the hippocampus, a region that has been identified as an important integration center in the development of learning and memory (9). In view of the special metabolic requirements of the hippocampus, it is not unexpected that hippocampal neurons exhibit robust expression of the neuron-specific glucose transporter GLUT3 (10) as well as the insulin-sensitive glucose transporter GLUT4 (11).Recent cloning of a novel mammalian glucose transporter was stimulated by the unexpected phenotypes of GLUT2 and GLUT4 knockout mice (12, 13) and by the ability to search databases for sequence similarities with GLUTs 1-5 (14). GLUTx1, also r...

Objectives Develop and test a theoretical acceptability model for the Nestorone®/ethinyl estradiol (NES/EE) contraceptive vaginal ring (CVR); explore whether domains of use within the model predict satisfaction, method adherence and CVR continuation. Study Design Four domains of use were considered relative to outcome markers of acceptability, i.e. method satisfaction, adherence, and continuation. A questionnaire to evaluate subjects’ experiences relative to the domains, their satisfaction (Likert scale), and adherence to instructions for use was developed and administered to 1036 women enrolled in a 13-cycle Phase 3 trial. Method continuation was documented from the trial database. Stepwise logistic regression (LR) analysis was conducted and odds ratios calculated to assess associations of satisfaction with questions from the 4 domains. Fisher’s exact test was used to determine the association of satisfaction with outcome measures. Results A final acceptability model was developed based on the following determinants of CVR satisfaction: ease of use, side effects, expulsions/feeling the CVR, and sexual activity including physical effects during intercourse. Satisfaction was high (89%) and related to higher method adherence [OR 2.6(1.3,5.2)] and continuation [OR5.5(3.5, 8.4)]. According to the LR analysis, attributes of CVR use representing items from the 4 domains — finding it easy to remove, not complaining of side effects, not feeling the CVR while wearing it, and experiencing no change or an increase in sexual pleasure and/or frequency — were associated with higher odds of satisfaction. Conclusion Hypothesized domains of CVR use were related to satisfaction, which was associated with adherence and continuation. Results provide a scientific basis for introduction and future research.

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Objective:To evaluate the safety and pharmacokinetics of MIV-150 and zinc acetate in a carrageenan gel (PC-1005). Acceptability, adherence, and pharmacodynamics were also explored.Design:A 3-day open-label safety run-in (n = 5) preceded a placebo-controlled, double-blind trial in healthy, HIV-negative, abstinent women randomized (4:1) to vaginally apply 4 mL of PC-1005 or placebo once daily for 14 days.Methods:Assessments included physical examinations, safety labs, colposcopy, biopsies, cervicovaginal lavages (CVLs), and behavioral questionnaires. MIV-150 (plasma, CVL, tissue), zinc (plasma, CVL), and carrageenan (CVL) concentrations were determined with LC-MS/MS, ICP-MS, and ELISA, respectively. CVL antiviral activity was measured using cell-based assays. Safety, acceptability, and adherence were analyzed descriptively. Pharmacokinetic parameters were calculated using noncompartmental techniques and actual sampling times. CVL antiviral EC50 values were calculated using a dose–response inhibition analysis.Results:Participants (n = 20) ranged from 19–44 years old; 52% were black or African American. Among those completing the trial (13/17, PC-1005; 3/3, placebo), 11/17 reported liking the gel overall; 7 recommended reducing the volume. Adverse events, which were primarily mild and/or unrelated, were comparable between groups. Low systemic MIV-150 levels were observed, without accumulation. Plasma zinc levels were unchanged from baseline. Seven of seven CVLs collected 4-hour postdose demonstrated antiviral (HIV, human papillomavirus) activity. High baseline CVL anti–herpes-simplex virus type-2 (HSV-2) activity precluded assessment of postdose activity.Conclusions:PC-1005 used vaginally for 14 days was well tolerated. Low systemic levels of MIV-150 were observed. Plasma zinc levels were unchanged. Postdose CVLs had anti-HIV and anti–human papillomavirus activity. These data warrant further development of PC-1005 for HIV and sexually transmitted infection prevention.

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