Introduction: Fasting has no adverse effects on healthy Muslims during Ramadan. However, it can induce serious complications for patients with type 2 diabetes (T2D). We aimed to follow the variation of some biochemical and clinical parameters in T2D patients before and after Ramadan; and to determine the incidence of fasting on hypoglycaemia and lactic acidosis associated with antidiabetic agents such as metformin.
View Article and Find Full Text PDFParkinson's disease is a neurodegenerative disorder caused by loss of dopamine neurons in the substantia nigra pars compacta. Tremor, rigidity, and bradykinesia are the major symptoms of the disease. These motor impairments are often accompanied by affective and emotional dysfunctions which have been largely studied over the last decade.
View Article and Find Full Text PDFEM66 is a peptide derived from the chromogranin, secretogranin II (SG-II). Recent findings in mice indicate that EM66 is a novel anorexigenic neuropeptide that regulates hypothalamic feeding behavior, at least in part, by activating the POMC neurons of the arcuate nucleus. The present study aimed to investigate the mechanism of action of EM66 in the control of feeding behavior and, more specifically, its potential interactions with the NPY and POMC systems in rat.
View Article and Find Full Text PDFEM66 is a conserved 66-amino acid peptide derived from secretogranin II (SgII), a member of the granin protein family. EM66 is widely distributed in secretory granules of endocrine and neuroendocrine cells, as well as in hypothalamic neurones. Although EM66 is abundant in the hypothalamus, its physiological function remains to be determined.
View Article and Find Full Text PDFJerboas are wild rodents exhibiting exceptional adaptation to their desert environment. Under harsh autumn conditions, they shut down reproduction, increase body weight and hibernate, while during spring they become sexually active even under negative energy-balance. We recently reported that these rhythms are associated with synchronized changes in genes expressing reproductive (Kiss1, Rfrp) and metabolic (Npy and Pomc) peptides, raising the hypothesis of coordinated seasonal regulation of both functions.
View Article and Find Full Text PDFThis work purpose was to estimate the implication of suspected adrenal function deficiencies, which was influenced by oxidative stress (OS) that are generating brain plasticity, and reorganization of the functional control. This phenomenon was revealed in two-hemodialysis patients described in this paper. Blood oxygenation level dependent functional magnetic resonance imaging (BOLD-fMRI) revealed a significant activation of the motor cortex.
View Article and Find Full Text PDFObjectives: The goal of this study was assessing the intermittent fasting effect on brain plasticity and oxidative stress (OS) using blood-oxygenation-level dependent (BOLD)-functional magnetic resonance image (fMRI) approach. Evidences of physiological and molecular phenomena involved in this process are discussed and compared to reported literature.
Method: Six fully healthy male non-smokers volunteered in this study.
The presence of mycotoxins in food is a major problem of public health as they produce immunosuppressive, hepatotoxic and neurotoxic effects. Mycotoxins also induce mutagenic and carcinogenic effects after long exposure. Among mycotoxins that contaminate food are aflatoxins (AF) such as AFB1, which is the most powerful natural carcinogen.
View Article and Find Full Text PDFPurpose: Hemodialysis (HD) is considered the most common alternative for overcoming renal failure. Studies have shown the involvement of HD membrane in the genesis of oxidative stress (OS) which has a direct impact on the brain tissue and is expected to be involved in brain plasticity and also reorganization of brain function control. The goal of this paper was to demonstrate the sensitivity of the blood oxygenation level-dependent functional magnetic resonance imaging (BOLD-fMRI) to characterize the OS before and after the HD session.
View Article and Find Full Text PDFAim: In prostate cancer (PCa), neuroendocrine differentiation (NED) is commonly observed in relapsing, hormone therapy-resistant tumours after androgen deprivation. However, the molecular mechanisms involved in the NED of PCa cells remain poorly understood. In this study, we investigated the expression of the neuroendocrine secretory protein secretogranin II (SgII) in PCa, and its potential involvement in the progression of this cancer as a granulogenic factor promoting NED.
View Article and Find Full Text PDFAnn Biol Clin (Paris)
October 2014
Drug response is often variable from an individual to another: the same dose of drug administered to different patients could cause variable pharmacological effects in nature and intensity. Those effects are often the result of variability in drugs pharmacokinetics (absorption, distribution, metabolism and elimination) which alter their bioavailability. In fact, two factors should be taken into account: the disease(s) from which the patient suffers, and the associated drugs, because many drug interactions may alter their pharmacokinetics causing consequently quite enough of different therapeutic effects.
View Article and Find Full Text PDFEM66 is a secretogranin II-derived peptide strongly expressed within hypothalamic neuroendocrine areas such as the parvocellular aspect of the paraventricular nucleus (pPVN) as well as the median eminence (ME), suggesting a hypophysiotropic role for this neuropeptide. The aim of the present study was to explore such a role in the corticotrope and thyrotrope axes. We analyzed EM66 occurrence respectively in CRH and TRH neurosecretory cells of the rat pPVN by double immunohistochemistry.
View Article and Find Full Text PDFThe jerboa is a semi-desert rodent, in which reproductive activity depends on the seasons, being sexually active in the spring-summer. The present study aimed to determine whether the expression of two RF-amide peptides recently described to regulate gonadotrophin-releasing hormone neurone activity, kisspeptin (Kp) and RF-amide-related peptide (RFRP)-3, displays seasonal variation in jerboa. Kp and/or RFRP-3 immunoreactivity was investigated in the hypothalamus of jerboas captured in the field of the Middle Atlas mountain (Morocco), either in the spring or autumn.
View Article and Find Full Text PDFAim: Accumulating data suggest that neuropeptides produced by neuroendocrine cells play a crucial role in the progression and aggressiveness of hormone refractory prostate cancer (CaP). In this study, we have investigated the presence and function of the neuropeptide 26RFa in CaP.
Methods: We have localised and quantified tumour cells containing 26RFa and its receptor, GPR103, in CaP sections of various grades.
Objectives And Methods: Neuropeptides, as the main neuroendocrine system effectors, regulate notably the response to different stressors via a secretory plasticity within their respective hypothalamic neuronal populations. The aim of the present study was to explore by immunocytochemistry the occurrence and the potential expression plasticity of the novel neuropeptide EM66 in the CRH neurones of stressed rats.
Results: The secretogranin II (SgII)-derived peptide EM66 is strongly expressed within hypothalamic neuroendocrine areas such as the parvocellular aspect of the paraventricular nucleus (pPVN) as well as the median eminence, suggesting a probable hypophysiotropic effect of this peptide.
The control of appetite and satiety is extremely complex and involves a balance between neurotransmitters and neuropeptides to stimulate and/or inhibit feeding behaviour. The effect of cannabinoids on food intake is well established, but little is known about the mechanism of action underlying their activity. In the present report, the effect of pharmacological manipulation of the cannabinoid receptor on the expression of hypothalamic neuropeptides is investigated.
View Article and Find Full Text PDFThe jerboa (Jaculus orientalis) has been described in the past as a hibernator, but no reliable data exist on the daily and seasonal rhythmicity of body temperature (T (b)). In this study, T (b) patterns were determined in different groups of jerboas (isolated males and females, castrated males and grouped animals) maintained in captivity during autumn and winter, and submitted to natural variations of light and ambient temperature (T (a)). T (b) and T (a) variations were recorded with surgically implanted iButton temperature loggers at 30-min intervals for two consecutive years.
View Article and Find Full Text PDFPheochromocytomas are rare catecholamine-secreting tumors that arise from chromaffin tissue within the adrenal medulla and extra-adrenal sites. Typical clinical manifestations are sustained or paroxysmal hypertension, severe headaches, palpitations and sweating resulting from hormone excess. However, their presentation is highly variable and can mimic many other diseases.
View Article and Find Full Text PDF26RFa is a hypothalamic RFamide neuropeptide that was identified as the endogenous ligand of the orphan G protein-coupled receptor, GPR103, and that stimulates appetite in mice. Up until now, the mechanism of action of 26RFa in the hypothalamic control of food intake remains unknown. The high density of GPR103 in the arcuate nucleus (Arc) prompted us to investigate, in the present study, the effects of 26RFa on the rat neuropeptide Y (NPY)/proopiomelanocortin (POMC) system.
View Article and Find Full Text PDFObjectives And Methods: The presence of oxytocin (OT) and its putative participation to the phenotypic plasticity of CRH neurones in the stressed jerboa was investigated. We analysed by immunocytochemistry the OT expression within the hypothalamic parvicellular paraventricular nucleus (pPVN) of male jerboas submitted to an acute immobilization (30 min).
Results: OT presence was clearly demonstrated in the pPVN of the jerboa and no significant difference in the number of OT immunolabeled cells was observed whatever the experimental conditions.
The corticotropin-releasing hormone (CRH) neurons of the hypothalamic parvocellular paraventricular nucleus (PVN) have a high potential for phenotypical plasticity, allowing them to rapidly modify their neuroendocrine output, depending upon the type of stressors. Indeed, these neurons coexpress other neuropeptides, such as cholecystokinin (CCK), vasopressin (VP), and neurotensin, subserving an eventual complementary function to CRH in the regulation of the pituitary. Unlike in rats, our previous data showed that in jerboas, CCK is not coexpressed within CRH neurons in control as well as stressed animals.
View Article and Find Full Text PDFEM66 is a 66-amino acid peptide derived from secretogranin II, a member of granin acidic secretory protein family, by proteolytic processing. EM66 has been previously characterized in the jerboa (Jaculus orientalis) hypothalamus and its potential implication in the neuroendocrine regulation of feeding behaviour has been demonstrated. In the present study, an immunohistochemical analysis of the localization of EM66 within hypothalamic structures of rat was performed and compared to the distribution of EM66 in the jerboa hypothalamus.
View Article and Find Full Text PDFThe hypothalamic response to an environmental stress implicates the corticotrophin-releasing hormone (CRH) neuroendocrine system of the hypothalamic parvicellular paraventricular nucleus (PVN) in addition to other neuropeptides coexpressed within CRH neurones and controlling the hypothalamo-pituitary-adrenal (HPA) axis activity as well. Such neuropeptides are vasopressin, neurotensin and cholecystokinin (CCK). It has previously been demonstrated that the majority of the CRH neuronal population coexpresses CCK after a peripheral stress in rats.
View Article and Find Full Text PDFThe neuroendocrine protein secretogranin II is the precursor of several neuropeptides, including secretoneurin and a novel 66-amino acid peptide, EM66, the sequence of which has been highly conserved across the vertebrae phylum. The presence of EM66 has been detected in the adult and fetal human adrenal gland, as well as the rat pituitary and adrenal glands. The present study aimed to explore a possible neuroendocrine role of EM66 by analysing its occurrence and distribution within the jerboa hypothalamus, and its potential implication in the control of feeding behaviour.
View Article and Find Full Text PDFThe distribution of neurons expressing beta-endorphin immunoreactivity was explored in the brain of adult jerboa during two distinct periods characterizing its reproductive cycle. A large presence of cell bodies displaying beta-endorphin immunoreactivity occured within different parts of the mediobasal hypothalamus along its rostrocaudal extent, from the retrochiasmatic area to the posterior arcuate nucleus. Quantitatively, the highest density of immunoreactive beta-endorphin neurons was noted at the medial level of the arcuate nucleus.
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