Effect of Caffeine on the Inflammatory-Dependent Changes in the GnRH/LH Secretion in a Female Sheep Model.

Caffeine is one of the most widely consumed psychoactive drugs in the world. It easily crosses the blood-brain barrier, and caffeine-interacting adenosine and ryanodine receptors are distributed in various areas of the brain, including the hypothalamus and pituitary. Caffeine intake may have an impact on reproductive and immune function.

Acute Effect of Caffeine on the Synthesis of Pro-Inflammatory Cytokines in the Hypothalamus and Choroid Plexus during Endotoxin-Induced Inflammation in a Female Sheep Model.

This study was designed to determine the effect of acute caffeine (CAF) administration, which exerts a broad spectrum of anti-inflammatory activity, on the synthesis of pro-inflammatory cytokines and their receptors in the hypothalamus and choroid plexus (ChP) during acute inflammation caused by the injection of bacterial endotoxin-lipopolysaccharide (LPS). The experiment was performed on 24 female sheep randomly divided into four groups: control; LPS treated (iv.; 400 ng/kg of body mass (bm.

Identification of Reference Genes for Circadian Studies on Brain Microvessels and Choroid Plexus Samples Isolated from Rats.

Delivery of putative compounds of therapeutic value to the brain is limited by brain barriers: the blood-brain barrier located in the endothelium of the brain microvessels (BrMVs) and the blood-cerebrospinal fluid barrier located in the epithelium of the choroid plexus (ChP). Understanding their function and modulation by the circadian clock may enhance the efficacy of brain-targeting therapies. The aim of the present study was to evaluate the stability of 10 reference genes in the BrMV and ChP, isolated from male and female rats at six time points (ZT1, 5, 9, 13, 17, and 21).

Effect of Lipopolysaccharide-Induced Inflammatory Challenge on β-Glucuronidase Activity and the Concentration of Quercetin and Its Metabolites in the Choroid Plexus, Blood Plasma and Cerebrospinal Fluid.

Quercetin-3-glucuronide (Q3GA), the main phase II metabolite of quercetin (Q) in human plasma, is considered to be a more stable form of Q for transport with the bloodstream to tissues, where it can be potentially deconjugated by β-glucuronidase (β-Gluc) to Q aglycone, which easily enters the brain. This study evaluates the effect of lipopolysaccharide (LPS)-induced acute inflammation on β-Gluc gene expression in the choroid plexus (ChP) and its activity in blood plasma, ChP and cerebrospinal fluid (CSF), and the concentration of Q and its phase II metabolites in blood plasma and CSF. Studies were performed on saline- and LPS-treated adult ewes ( = 40) receiving Q3GA intravenously ( = 16) and on primary rat ChP epithelial cells and human ChP epithelial papilloma cells.

Photoperiod Affects Leptin Action on the Choroid Plexus in Ewes Challenged with Lipopolysaccharide-Study on the mRNA Level.

The ovine choroid plexus (ChP) expresses the long isoform of the leptin receptor, which makes this structure a potential target for leptin action. In sheep, leptin concentration in plasma is higher during long days (LD) than short days (SD). This study evaluates the influence a of photoperiod on leptin impact on the gene expression of Toll-like receptor 4 (), proinflammatory cytokines (, ), their receptors (, , , , ) and inflammasome components necessary for pro-IL-1β activation (, , ), chemokine (), leptin receptor isoforms (, ) and a suppressor of cytokine signalling () in the ChP of ewes treated or not with lipopolysaccharide (LPS).

Neostigmine Attenuates Proinflammatory Cytokine Expression in Preoptic Area but Not Choroid Plexus during Lipopolysaccharide-Induced Systemic Inflammation.

The study was designed to examine whether the administration of neostigmine (0.5 mg/animal), a peripheral inhibitor of acetylcholinesterase (AChE), during an immune/inflammatory challenge provoked by intravenous injection of bacterial endotoxin-lipopolysaccharide (LPS; 400 ng/kg)-attenuates the synthesis of proinflammatory cytokines in the ovine preoptic area (POA), the hypothalamic structure playing an essential role in the control of the reproduction process, and in the choroid plexus (CP), a multifunctional organ sited at the interface between the blood and cerebrospinal fluid in the ewe. Neostigmine suppressed ( < 0.

Plasma and cerebrospinal fluid interleukin-1β during lipopolysaccharide-induced systemic inflammation in ewes implanted or not with slow-release melatonin.

Background: Interleukin-1β (IL-1β) is important mediator of inflammatory-induced suppression of reproductive axis at the hypothalamic level. At the beginning of inflammation, the main source of cytokines in the cerebrospinal fluid (CSF) is peripheral circulation, while over time, cytokines produced in the brain are more important. Melatonin has been shown to decrease pro-inflammatory cytokines concentration in the brain.

PCB153 (2,2',4,4',5,5'-hexachlorobiphenyl) differentially affects the VEGF/VEGFR system depending on photoperiod in the ovine choroid plexus.

Ortho-substituted polychlorinated biphenyls (PCBs) preferentially accumulate in the brain and cerebrospinal fluid (CSF) compared with other PCBs. We previously demonstrated in ewes that an identical dose of PCB153, the most environmentally prevalent congener, resulted in a higher plasma concentration during short days (SD: 1200pg/ml) than during long days (LD: 200pg/ml). Moreover, PCB153 treatment only reduced the SD tight junction protein content in the choroid plexus (CP), which was followed by a significant increase of the PCB153 concentration in the CSF.

Profile of toll-like receptor mRNA expression in the choroid plexus in adult ewes.

The blood-cerebrospinal fluid barrier (BCSFB) located in the epithelial cells of the choroid plexus (CP) forms the interface between the cerebrospinal fluid (CSF) and pathogen components circulating in the blood. The CP is also implicated in the passage of peripheral immune signals and circulation of immune cells into the central nervous system. Toll-like receptors (TLRs) are patternrecognition receptors that play a crucial role in the recognition of pathogens and triggering of the innate immune response.

Effect of a two-week treatment with a low dose of 2,2'4,4',5,5'-hexachlorobiphenyl (PCB153) on tight junction protein expression in ovine choroid plexus during long and short photoperiods.

Ortho-substituted polychlorinated biphenyls (PCBs) preferentially accumulate in the brain and cerebrospinal fluid (CSF) compared to other PCBs. We previously reported that the same dose of 2,2',4,4',5,5'-hexachlorobiphenyl (PCB153) induced higher concentrations in the CSF of treated animals compared to controls during short days (SD), while no differences were observed during long days (LD). Similarly, the plasma concentration of PCB153 in treated ewes was higher during SD than LD.

Pattern of expression of vascular endothelial growth factor and its receptors in the ovine choroid plexus during long and short photoperiods.

Vascular endothelial growth factor (VEGF-A) plays an important role in maintaining cerebrospinal fluid (CSF) homeostasis and the function of the choroid plexuses (CPs). The objective of the study was to determine the expression of vascular endothelial growth factor (VEGF-A), tyrosine kinase receptors Flt-1 and KDR and KDR co-receptor neuropilin 1 (NRP-1) in ovine CPs during different photoperiods. CPs were collected from the lateral brain ventricles from ovariectomized, estradiol-treated ewes during long day (LD; 16L:8D, n = 5) and short day (SD; 8L:16D, n = 5) photoperiods.

Photoperiod modulates access of 2,2',4,4',5,5'-hexachlorobiphenyl (PCB153) to the brain and its effect on gonadotropin and thyroid hormones in adult ewes.

The effects of photoperiod on the cerebrospinal fluid (CSF) concentration of six ortho-substituted polychlorinated biphenyls (PCBs: PCB28, PCB52, PCB101, PCB138, PCB153, and PCB180), the effects of an orally administered low dose of PCB153 (0.3mg/kg, three times a week for three weeks) on PCBs and thyroid hormones (THs) concentrations in the CSF and plasma, and the release of luteinizing hormone (LH) were determined in ovariectomized, estradiol-implanted ewes (2.5 years old) maintained indoors under artificial long day (LD, 16L: 8D) and short day (SD, 8L: 16D) conditions.

Tight junction proteins vary in the choroid plexus of ewes according to photoperiod.

Sheep from temperate latitudes exhibit seasonal variations in many physiological functions such as reproduction, food intake, body weight, and pelage growth. Majority of seasonal changes are controlled by the annual photoperiodic cycle and melatonin secretion. For reproduction, the resulting key event is a modulation of the negative feedback of steroids on gonadotropin secretion.