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Content available remote Simulation of neurotransmitter transport in a presynaptic bouton of a neuron
In this paper the results of numerical simulation of neuro-transmitter fast transport in a presynaptic bouton of a biological neuron are presented. A mathematical model governing the transport that is fully described in [2] is recalled. A numerical simulation scheme, used parameters and their origins arę described. Finally, the results of the simulation are presented.
An enhanced microdialysis method for neuropeptides is described and some prelimi­nary results of this novel approach are presented. The enhancement is achieved by adding a vehicle (solid support) to the perfusion fluid in order to increase the diffusion coefficient across the membrane and efficiently transport the analytes towards the de­tector. The microdialysis samples are desalted and then analyzed on an electrospray ionization orthogonal time-of-flight mass spectrometer. The preliminary results show major increase in signal when comparing this new approach of microdialysis with or­dinary microdialysis.
Histamine, acting centrally as a neurotransmitter, evokes a reversal of haemorrhagic shock in rats due to the activation of the sympathetic and the renin-angiotensin systems as well as the release of arginine vasopressin and proopiomelanocortin-derived peptides. In the present study, we demonstrate influences of cholinergic receptor antagonists on the central histamine-induced resuscitating action. Experiments were carried out in male anaesthetised Wistar rats subjected to a haemorrhagic hypotension of 20-25 mmHg, resulting in the death of all control animals within 30 min. Histamine (100 nmol) administered intracerebroventricularly (icv) at 5 min of critical hypotension produced a long-lasting pressor effect with increases in heart rate and peripheral blood flows, and a 100% survival at 2 h. Mean arterial pressure and blood flow changes were almost completely blocked by nicotinic receptor antagonist mecamylamine (246.3 nmol; icv) and partially inhibited by muscarinic receptor blocker atropine sulphate (14.8 nmol; icv). Cholinergic receptor antagonists given alone in the control saline-treated groups did not affect cardiovascular parameters in the post-bleeding period. In conclusion, there are interactions between the histaminergic and cholinergic systems, with an involvement of both nicotinic and muscarinic receptors, in the central cardiovascular regulation in haemorrhagic hypotension in rats.
Open Medicine
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Multiple sclerosis is still a disease without a cure. Although intensive research efforts have led to the development of drugs that modify the activity of the disease, most of them have various side effects and are expensive. At the same time it is becoming apparent that some remedies usually used to treat somatic and psychic disorders also have immunomodulating properties, and may help manage multiple sclerosis and other autoimmune diseases. We describe here the role of the sympathetic nervous system in the neuro-immune interaction in multiple sclerosis and other immune diseases with increased cellular immunity as well as neurochemical disturbances that take place in these disorders.
White communicating rami were traced in 8 human embryos of developmental stages 14 and 15 (aged 33 and 36 postovulatory days, respectively). In embryos at stage 14 the white communicating rami were found in the spinal nerves T1 to T9. In embryos at stage 15 the white communicating rami were present at the spinal cord levels T1 to L3. (Folia Morphol 2010; 69, 2: 75–77)
Background: The cholinergic neurotransmission within the human mesenteric lymphatic vessels has been poorly studied. Therefore, our aim is to analyse the cholinergic nerve fibres of lymphatic vessels using the traditional enzymatic techniques of staining, plus the biochemical modifications of acetylcholinesterase (AChE) activity. Materials and methods: Specimens obtained from human mesenteric lymphatic vessels were subjected to the following experimental procedures: 1) drawing, cutting and staining of tissues; 2) staining of total nerve fibres; 3) enzymatic staining of cholinergic nerve fibres; 4) homogenisation of tissues; 5) biochemical amount of proteins; 6) biochemical amount of AChE activity; 6) quantitative analysis of images; 7) statistical analysis of data. Results: The mesenteric lymphatic vessels show many AChE positive nerve fibres around their wall with an almost plexiform distribution. The incubation time was performed at 1 h (partial activity) and 6 h (total activity). Moreover, biochemical dosage of the same enzymatic activity confirms the results obtained with morphological methods. Conclusions: The homogenates of the studied tissues contain strong AChE activity. In our study, the lymphatic vessels appeared to contain few cholinergic nerve fibres. Therefore, it is expected that perivascular nerve stimulation stimulates cholinergic nerves innervating the mesenteric arteries to release the neurotransmitter AChE, which activates muscarinic or nicotinic receptors to modulate adrenergic neurotransmission. These results strongly suggest, that perivascular cholinergic nerves have little or no effect on the adrenergic nerve function in mesenteric arteries. The cholinergic nerves innervating mesenteric arteries do not mediate direct vascular responses. (Folia Morphol 2013; 72, 4: 322–327)
The serotonin transporter (SERT) has shown itself to be an effective pharmacological target in the treatment of mood disorders and some kinds of gastrointestinal syndromes. Most of the molecular studies of SERT in humans have been carried out using heterologous models. In this work, we have investigated the human enterocyte-like Caco-2 cell line as a potential "in vitro" model to study the human SERT. The results show that these cells express a SERT mRNA identical to the human brain SERT, and a 70 kDa protein immunodetected using a specific antibody. The SERT activity levels in Caco-2 cells increased in correlation with the onset and maintenance of the morphological and functional differentiation of the cells. Caco-2 SERT was also shown to be a high affinity (Kt=0.216 µM) saturable, Na+-dependent transporter that was inhibited by fluoxetine (IC50=17.6 nM). In addition, SERT activity was inhibited by the intracellular modulators protein kinase C and cAMP, either after short or long-term treatment. In short, the expression and molecular characteristics of the human SERT in Caco-2 cells indicate that this cell line may be an ideal tool to study in vitro the physiology and pharmacology of human SERT.
Changes in the large neutral amino acid (LNAA) transport across the blood-brain barrier (BBB) is thought to contribute to brain dysfunction in a number of clinical conditions, including phenylketonuria, acute liver failure, and sepsis. Here, we present a novel approach for estimating BBB permeability and the LNAA concentrations in brain extracellular fluid, by demonstrating that they can be mathematically derived on the basis of kinetic constants of the BBB available from the literature, if cerebral blood flow and the arterial and jugular venous LNAA concentrations are known. While it is well known that the permeability surface area product of the BBB to a LNAA from blood to brain (PS1) can be calculated from the arterial LNAA concentrations and kinetic constants of the BBB, we demonstrate that the permeability surface area product from brain to blood (PS2) can be calculated by deriving the substrate activity of the saturable transporter from the kinetic constants and arterial and jugular venous LNAA concentrations, and that the concentration of the LNAA in brain extracellular fluid can then be determined. This approach is methodically simple, and may be useful for assessing the transcerebral exchange kinetics of LNAAs in future human-experimental and clinical studies.
Bób jest jedną z najdłużej uprawianych roślin na świecie, lecz wciąż niedocenioną w wielu krajach. Nasiona bobu są wykorzystywane zarowno jako pasza dla zwierząt, jak i żywność dla ludzi. W Polsce jest uprawiany na niewielką skalę i spożywa się go głownie sezonowo. Największym producentem nasion bobu są Chiny. Znikoma zawartość tłuszczu w nasionach sprawia, że może być stosowany przez osoby stosujące diety niskotłuszczowe, a dzięki wysokiej zawartości białka może stanowić substytut mięsa w diecie wegetariańskiej. Nasiona bobu zawierają także związki antyodżywcze, takie jak saponiny, lektyny, inhibitory proteaz czy kwas fitynowy. Bob może pełnić ważną funkcję w prewencji chorób neurodegeneracyjnych jako źrodło prekursorów neuroprzekaźników. Zawiera l-3,4-dihydrosyfenyloalaninę, związek stosowany w leczeniu cierpiących na chorobę Parkinsona. Brak efektów ubocznych, często występujących przy podawaniu syntetycznej formy tego związku, jest zaletą stosowania tej rośliny w terapii. Niektóre technologie fermentacji zwiększają ilość prekursorów neurotransmiterów.
The faba bean is one of the longest-cultivated plants in the world but still underestimated in many countries. It is used as feed and food. In Poland, these beans are grown on a small scale and they are mainly eaten seasonally. China is the largest producer of faba bean. Low content of fat causes it is suitable for people on low-fat diet. Thanks to high content of protein it can be consumed by vegetarian as an alternative to meat. The discussed beans contain some antinutrients like: saponins, lectins, protease inhibitors and fitic acid. Faba beans can play an important role in the prevention of neurodegenerative diseases as a source of neurotransmitter precursors. It contains l-3,4-dihydroxyphenyloalanin, the compound used in the treatment of patients suffering from Parkinson’s disease. No side effects which often occur while dosing a synthetic form of this compound is a major advantage of the application of this plant in therapy. Some fermentation technologies increase the amount of neurotransmitter precursors.
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