scholarly journals Two distinct mechanisms for redistribution of lymphocyte surface macromolecules. II. Contrasting effects of local anesthetics and a calcium ionophore.

1978 ◽  
Vol 79 (2) ◽  
pp. 419-426 ◽  
Author(s):  
J Braun ◽  
K Fujiwara ◽  
T D Pollard ◽  
E R Unanue
Keyword(s):  
Local Anesthetic ◽  
Local Anesthetics ◽  
Calcium Ionophore ◽  
Contractile Proteins ◽  
Fc Receptor ◽  
Ionophore A23187 ◽  
Surface Complexes ◽  
Surface Molecules ◽  
Lymphocyte Surface ◽  
Dependent Link

In the previous study, lymphocyte surface molecules were separated into two subsets depending on whether capping was associated was associated with redistribution of cytoplasmic myosin. In the present study, the effects of the local anesthetic chlorpromazine and of the Ca2+ ionophore A23187 were compared. Both drugs affected the surface redistribution of immunoglobulin (Ig), Fc receptors, and the TL antigen--molecules that appear to cap by association with microfilaments--but had no effect on the Thy.1 (theta) and H2 antigens--molecules that cap slowly, apparently unlinked to microfilament function. The capping of Ig, Fc receptor, and TL was inhibited while that of H2 and theta was not. Both drugs reversed the Ig Fc receptor, and TL caps but not the H2 and theta caps. In the former group, the reversal of caps was accompanied by a parallel reversal of the myosin segregated to the cap area. The appearance of myosin after drug treatment varied: chlorpromazine resulted in a diffuse pattern similar to that of normal lymphocytes, whereas A23187 produced an array of aggregates and coarse filaments. The results are compatible with the view that two mechanisms for capping exist in the lymphocyte. The Ca2+ ionophore may affect capping of microfilament-dependent caps by producing a systemic activation of contractile proteins while chlorpromazine may act by disrupting a Ca2+-dependent link between surface complexes and the contractile proteins.

scholarly journals Mechanism of Fc-mediated interaction of eosinophils with immobilized immune complexes: I. Effects of inhibitors and activators of eosinophil function

1982 ◽  
Vol 56 (1) ◽  
pp. 337-356
Author(s):  
R.C. Oliver ◽  
A.M. Glauert ◽  
K.J. Thorne
Keyword(s):  
Protein A ◽  
Fc Receptors ◽  
Calcium Ionophore ◽  
Apparent Molecular Weight ◽  
Direct Consequence ◽  
Fc Receptor ◽  
Calcium Ionophore A23187 ◽  
Cytochalasin D ◽  
Ionophore A23187 ◽  
Staphylococcal Protein A

A protein of apparent molecular weight 55000, designated protein 3, becomes newly detectable on the eosinophil surface as a specific consequence of interaction with antigen-antibody complexes immobilized in agar layers. The effect of various agents upon this interaction has been determined by monitoring the appearance of this protein by lactoperoxidase-catalysed iodination. Other parameters that have been measured include: the attachment of eosinophils to the agar layers and their subsequent degranulation, as measured by the release of granule peroxidase, and the degree of spreading of the eosinophils, as assessed by electron microscopy. Attachment of eosinophils to antibody-coated layers is inhibited by heat-aggregated immunoglobulin G (IgG), suggesting that this attachment is mediated via eosinophil Fc receptors. In addition, agents, such as the eosinophil chemotactic factor Ala-Gly-Ser-Glu, that enhance the expression of Fc receptors also enhance the appearance of protein 3, while agents, such as hydrocortisone, that inhibit the expression of Fc receptors reduce its appearance. It is concluded that the appearance of protein 3 parallels the expression of Fc receptors. Attempts to block the Fc region of the bound antibody with staphylococcal protein A were not successful. These experiments indicated that the Fc region of bound IgG has different binding sites for protein A and for the Fc receptor. The correlation between the appearance of protein 3 and subsequent degranulation of the eosinophils was confirmed by the use of agents, such as cytochalasin D and levamisole, that enhance both the appearance of protein 3 and degranulation. Conversely, hydrocortisone reduces the appearance of protein 3 and inhibits degranulation. Protein 3 does not appear when eosinophils adhere to agar layers coated with concanavalin A instead of antibody and the eosinophils do not degranulate. Addition of the calcium ionophore A23187, while causing the release of granule peroxidase, does not elicit the appearance of protein 3. These observations provided additional evidence that the appearance of protein 3 is a specific consequence of the interaction of eosinophils with antibody-coated surfaces. The fact that protein 3 appears at the eosinophil surface as a direct consequence of the interaction with antibody suggests that this protein is closely associated with the eosinophil Fc receptor. The enhancement of the appearance of protein 3 in the presence of cytochalasin D indicates that the movement and reorientation of both this protein and the Fc receptor are constrained by association with cytoplasmic microfilaments.

Intracellular Calcium Ions Modulate Permeability of the Peritoneal Mesothelium In Vitro

1985 ◽  
Vol 5 (2) ◽  
pp. 105-108 ◽  
Author(s):  
Andrzej Breborowicz ◽  
Jan Knapowski ◽  
Grzegorz Breborowicz
Keyword(s):  
Epithelial Cells ◽  
Intracellular Calcium ◽  
Local Anesthetic ◽  
Calcium Ions ◽  
Calcium Transport ◽  
Calcium Ionophore ◽  
Ionophore A23187 ◽  
Peritoneal Mesothelium ◽  
Vitro Effect

The authors studied the in vitro effect of a calcium-channel-blocker -verapamil, local anesthetic -bupivacaine and a calcium ionophore -A23187 on the permeability of the monolayer mesothelium from the rabbit's mesentery. Verapamil and bupivacaine increased transmesothelial flux of calcium while A23187 increased calcium transport only transiently. Verapamil augmented the permeability of the mesothelium to inulin and urea. However A23187 decreased the transmesothelial flux of inulin only whereas it increased the transport of urea. From this study we have concluded, that intracellular calcium may determine the permeability of the peritoneal mesothelium. Various important biological processes like muscle contraction, secretion of transmitters and hormones, and control of epithelial permability seem to be dependent on intracellular calcium-ion activity (1–4). Our previous paper suggested that a local anesthetic, bupivacaine, produces its effect on the peritoneal mesothelium through interaction with the cytoskeleton of the epithelial cells, and with the mem brane's calcium transport (5). In addition Palant et al found that the permeability of another leaky epithelium, that from the Necturus gallbladder, depends on the extracellular calcium concentrations and may be altered by drugs, which interfere with the entrance of these ions into the epithelial cells (6). Therefore, we decided to study the role that calcium ions may play in the transport of solutes across the peritoneal mesothelium in vitro.

Growth factors and the primary cilium in BALB/c 3T3 cells

1987 ◽  
Vol 45 ◽  
pp. 830-831
Author(s):  
R. W. Tucker ◽  
N. S. More ◽  
S. Jayaraman
Keyword(s):  
Growth Factors ◽  
Primary Cilium ◽  
Cultured Cells ◽  
Morphological Changes ◽  
Calcium Ionophore ◽  
Growth Stimulation ◽  
Calcium Ionophore A23187 ◽  
Ionophore A23187 ◽  
3T3 Cells ◽  
Microtubule Depolymerization

The mechanisms by which polypeptide growth factors Induce DNA synthesis in cultured cells is not understood, but morphological changes Induced by growth factors have been used as clues to Intracellular messengers responsible for growth stimulation. One such morphological change has been the transient disappearance of the primary cilium, a “9 + 0” cilium formed by the perinuclear centriole in interphase cells. Since calcium ionophore A23187 also produced both mitogenesis and ciliary changes, microtubule depolymerization might explain ciliary disappearance monitored by indirect immunofluorescence with anti-tubulin antibody. However, complete resorption and subsequent reformation of the primary cilium occurs at mitosis, and might also account for ciliary disappearance induced by growth factors. To settle this issue, we investigated the ultrastructure of the primary cilium using serial thin-section electron microscopy of quiescent BALB/c 3T3 cells before and after stimulation with serum.

Inhibition of Platelet Aggregation by Ethanol in Vitro Shows Specificity for Aggregating Agent Used and Is Influenced by Platelet Lipid Composition

1982 ◽  
Vol 48 (01) ◽  
pp. 049-053 ◽  
Author(s):  
C G Fenn ◽  
J M Littleton
Keyword(s):  
Platelet Aggregation ◽  
Lipid Composition ◽  
Saturated Fatty Acids ◽  
Calcium Ionophore ◽  
Cholesterol Content ◽  
Membrane Lipid ◽  
Calcium Ionophore A23187 ◽  
Ionophore A23187 ◽  
Increased Sensitivity

SummaryEthanol at physiologically tolerable concentrations inhibited platelet aggregation in vitro in a relatively specific way, which may be influenced by platelet membrane lipid composition. Aggregation to collagen, calcium ionophore A23187 and thrombin (low doses) were often markedly inhibited by ethanol, adrenaline and ADP responses were little affected, and aggregation to exogenous arachidonic acid was actually potentiated by ethanol. Aggregation to collagen, thrombin and A23187 was inhibited more by ethanol in platelets enriched with saturated fatty acids than in those enriched with unsaturated fats. Platelets enriched with cholesterol showed increased sensitivity to ADP, arachidonate and adrenaline but this increase in cholesterol content did not appear to influence the inhibition by ethanol of platelet responses. The results suggest that ethanol may inhibit aggregation by an effect on membrane fluidity and/or calcium mobilization resulting in decreased activity of a membrane-bound phospholipase.

Local Anesthetics – Substances with Multiple Application in Medicine

2016 ◽  
Vol 4 (1) ◽  
pp. 17
Author(s):  
Rodica Sîrbu ◽  
Emin Cadar ◽  
Cezar Laurențiu Tomescu ◽  
Cristina Luiza Erimia ◽  
Stelian Paris ◽  
...  
Keyword(s):  
Peripheral Nerve ◽  
Medical Care ◽  
Local Anesthesia ◽  
Short Duration ◽  
Local Anesthetic ◽  
Local Anesthetics ◽  
Nerve Roots ◽  
Nervous Control ◽  
Painful Sensation ◽  
Action Groups

Local anesthetics are substances which, by local action groups on the runners, cause loss of reversible a painful sensation, delimited corresponding to the application. They allow small surgery, short in duration and the endoscopic maneuvers. May be useful in soothe teething pain of short duration and in the locking of the nervous disorders in medical care. Local anesthesia is a process useful for the carrying out of surgery and of endoscopic maneuvers, to soothe teething pain in certain conditions, for depriving the temporary structures peripheral nervous control. Reversible locking of the transmission nociceptive, the set of the vegetative and with a local anesthetic at the level of the innervations peripheral nerve, roots and runners, a trunk nervous, around the components of a ganglion or coolant is cefalorahidian practice anesthesia loco-regional. Local anesthetics summary and semi-summary have multiple applications in dentistry, consulting, surgery and obstetrics, constituting "weapons" very useful in the fight against the pain.

scholarly journals Lidocaine: A Local Anesthetic, Its Adverse Effects and Management

Medicina ◽  
2021 ◽  
Vol 57 (8) ◽  
pp. 782
Author(s):  
Entaz Bahar ◽  
Hyonok Yoon
Keyword(s):  
Adverse Effects ◽  
Local Anesthetic ◽  
Local Anesthetics ◽  
Adverse Reactions ◽  
Rapid Diagnosis ◽  
Diagnosis And Treatment ◽  
Allergic Reactions ◽  
Life Threatening

The most widely used medications in dentistry are local anesthetics (LA), especially lidocaine, and the number of recorded adverse allergic responses, particularly of hazardous responses, is quite low. However, allergic reactions can range from moderate to life-threatening, requiring rapid diagnosis and treatment. This article serves as a review to provide information on LA, their adverse reactions, causes, and management.

scholarly journals Local Anesthetic-Induced Central Nervous System Toxicity during Interscalene Brachial Plexus Block: A Case Series Study of Three Patients

2021 ◽  
Vol 10 (5) ◽  
pp. 1013
Author(s):  
Daniel Spitzer ◽  
Katharina J. Wenger ◽  
Vanessa Neef ◽  
Iris Divé ◽  
Martin A. Schaller-Paule ◽  
...  
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Brachial Plexus ◽  
Local Anesthetic ◽  
Local Anesthetics ◽  
Brachial Plexus Block ◽  
Central Nervous System Toxicity ◽  
Interscalene Brachial Plexus Block ◽  
Plexus Block ◽  
System Toxicity

Local anesthetics are commonly administered by nuchal infiltration to provide a temporary interscalene brachial plexus block (ISB) in a surgical setting. Although less commonly reported, local anesthetics can induce central nervous system toxicity. In this case study, we present three patients with acute central nervous system toxicity induced by local anesthetics applied during ISB with emphasis on neurological symptoms, key neuroradiological findings and functional outcome. Medical history, clinical and imaging findings, and outcome of three patients with local anesthetic-induced toxic left hemisphere syndrome during left ISB were analyzed. All patients were admitted to our neurological intensive care unit between November 2016 and September 2019. All three patients presented in poor clinical condition with impaired consciousness and left hemisphere syndrome. Electroencephalography revealed slow wave activity in the affected hemisphere of all patients. Seizure activity with progression to status epilepticus was observed in one patient. In two out of three patients, cortical FLAIR hyperintensities and restricted diffusion in the territory of the left internal carotid artery were observed in magnetic resonance imaging. Assessment of neurological severity scores revealed spontaneous partial reversibility of neurological symptoms. Local anesthetic-induced CNS toxicity during ISB can lead to severe neurological impairment and anatomically variable cerebral lesions.

Effects of glucocorticoids on prostaglandin formation by human amnion

1990 ◽  
Vol 68 (6) ◽  
pp. 671-676 ◽  
Author(s):  
William Gibb ◽  
Jean-Claude Lavoie
Keyword(s):  
Calcium Ionophore ◽  
Inhibitory Effect ◽  
Calcium Ionophore A23187 ◽  
Ionophore A23187 ◽  
Isolated Cells ◽  
Stimulatory Action ◽  
Human Amnion ◽  
Human Labor ◽  
Epidermal Growth

The human amnion may be an important source of prostaglandins involved in the onset of human labor and therefore it is important to define the factors that regulate their formation in this tissue. In the present study we demonstrate that glucocorticoids inhibit prostaglandin production by freshly isolated amnion cells. The inhibitory action of the glucocorticoids, however, changes to a stimulatory action when the cells are maintained in primary culture for a few days. For both inhibition and stimulation, concentrations of 10−8 M dexamethasone or greater were required to give significant effects, and estradiol and progesterone had no effect on the prostaglandin output of the cells. Epidermal growth factor (EGF), which has previously been found to stimulate prostaglandin output by confluent amnion cells, did not alter prostaglandin output of cells initially placed in culture. Furthermore, the stimulatory action of EGF and dexamethasone appeared additive. The calcium ionophore A23187 stimulated prostaglandin output in freshly isolated cells and accentuated the inhibitory effect of dexamethasone. These studies indicate that prostaglandin formation by human amnion during pregnancy could be regulated by glucocorticoids. These steroids are easily available to the amnion by way of cortisone conversion to Cortisol by the maternal decidua. The results also indicate that amnion is capable of responding to glucocorticoids in both a stimulatory and inhibitory fashion and whether one or both actions are of importance in vivo is a question that is as yet unresolved.Key words: prostaglandins, amnion, fetal membranes, glucocorticoids, labor, pregnancy.

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