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Cleistanthin A and B block the alpha adrenergic and nicotinic cholinergic receptors, but these compounds do not interact at all with the beta adrenergic and muscarinic cholinergic receptors.
These observations indicate that felbamate block of NMDA receptors does not occur by an action at the glycine site.
Journal ArticleDOI
Shlomo Raz, Marcia Zeigler, Marco Caine 
01 Dec 1973-BJUI
91 Citations
By virtue of the fact that these substances occupy the sites of the receptors, they block the access of the agonists, and are thus known as “blockers.”
Additivity experiments suggest that ten 5-HT3 receptor blockers tested at low concentrations preferentially block subtypes of GABAA receptors that are among those blocked by clozapine.
Therefore, besides their depolarizing action, ACh, nicotine and oxotremorine could eliminate the magnesium block of NMDA receptors by activation of protein kinase C.
The receptor loss is not additive with that seen in the presence of either cycloheximide or tunicamycin, two compounds that the block appearance of new receptors.
We demonstrate that drugs classically known as competitive nACh receptor antagonists also block 5-HT(3A) receptors.
This suggests that all of these antipsychotic/antidepressant drugs may block a common subset of GABAA receptors.
Therefore neuromuscular relaxants may block 5-HT(3A) receptors.
The apparent competitive mode of block induced by Zn2+ on α1β1δ receptors is shared by GABAA receptors on cerebellar granule neurones, which are known to express δ‐subunit‐containing receptors.

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How CBD is absorbed in the gut?
5 answers
Cannabidiol (CBD) absorption in the gut is influenced by several factors, including the presence of food, the formulation of CBD, and the activity of the endocannabinoid system. Studies have shown that the bioaccessibility of CBD significantly increases when consumed with food, particularly high-fat meals, which enhance its micellarization efficiency and, consequently, its absorption through the gut wall. This is attributed to the lipase enzyme activity and the presence of bile salts, which facilitate the formation of micelles from hydrolyzed lipids, aiding in the bioaccessibility of hydrophobic molecules like CBD. Furthermore, the development of novel nanoemulsion preparations of CBD has been shown to improve its poor solubility and absorption, demonstrating a significant increase in the area under the curve (AUC) and maximum concentration (Cmax) in pharmacokinetic profiles compared to conventional CBD oil formulations. This suggests that nanoemulsion formulations can enhance CBD absorption regardless of bile secretion, which is essential for the micelle formation required for the absorption of conventional CBD oil. The endocannabinoid system also plays a crucial role in the absorption and bioavailability of CBD. Activation of cannabinoid receptors in the gut can influence gastrointestinal motility and secretion, potentially affecting the absorption of CBD. Moreover, the modulation of this system can impact the permeability of the intestinal epithelium, which is critical for the absorption of substances from the gut. In summary, CBD absorption in the gut is enhanced by the presence of food, particularly fats that stimulate bile and lipase activity, improving CBD's solubility and bioaccessibility. Nanoemulsion formulations further enhance CBD absorption by overcoming its poor solubility. Additionally, the endocannabinoid system's modulation of gut permeability and motility may also influence CBD absorption.
What role does the duration of curare exposure play in determining the risk of residual paralysis in patients?
4 answers
The duration of curare exposure can significantly impact the risk of residual paralysis in patients. Curare, specifically d-Tubocurarine, acts as a potent reversible competitive antagonist at nicotinic acetylcholine receptors, causing rapid flaccid paralysis of skeletal muscle when parenterally administered. Studies have shown that postoperative residual curarisation (PORC) is a common complication, with an incidence rate of 45.5% in some settings. Factors like advanced age and female gender have been associated with a higher risk of residual paralysis, emphasizing the need for routine quantitative monitoring of neuromuscular function to minimize this preventable condition. While modern neuromuscular blocking drugs have improved in terms of stability and predictability, residual paralysis remains a clinically significant issue, highlighting the importance of monitoring and managing curare exposure duration to mitigate risks.
What is milk exosom?
4 answers
Milk exosomes are natural nanoparticles derived from the endocytic system and are present in bovine milk. These exosomes play a crucial role in cell-to-cell communication by transferring various bioactive compounds like RNAs, lipids, and proteins. They exhibit high stability in the gastrointestinal tract, resist degradation during milk processing, and can be absorbed, accumulating in tissues after oral administration. Milk exosomes have gained attention for their potential in delivering therapeutic agents, including small drug molecules and siRNA, to combat diseases like cancer. Due to their unique properties, milk exosomes are being explored as promising tools for drug delivery systems, particularly in personalized therapy. The isolation techniques, physicochemical properties, and biodistribution of milk exosomes make them attractive candidates for innovative drug delivery strategies.
What is the concentration of VEGF in EGM-2 medium from Lonza?
5 answers
The concentration of VEGF in EGM-2 medium from Lonza is not explicitly mentioned in the provided contexts. However, the contexts discuss the formulation of high-concentration anti-VEGF antibodies in aqueous pharmaceutical compositions suitable for injection. These compositions are designed to deliver a high concentration of the antibody active ingredient without significant levels of aggregation or sub-visible particulate matter. The formulations typically contain antibodies with a concentration of at least 50 mg/ml, along with sugars, buffering agents, and surfactants. While the exact concentration of VEGF in EGM-2 medium is not specified in the contexts, the information provided highlights the importance of high-concentration formulations for effective delivery of anti-VEGF antibodies.
Is phosphatidil serine useful for seizure?
5 answers
Phosphatidylserine (PS) has therapeutic potential beyond seizures. PS is beneficial for regressive brain diseases, aiding in liposome preparation and dietary therapy. PS receptors play a role in reducing inflammation, treating autoimmune diseases, enhancing tissue graft transplantation, increasing anti-tumor immunity, and inhibiting infections. Additionally, tumor-derived PS affects macrophages, reducing their ability to produce nitric oxide and lyse tumor targets. Interestingly, a parasite, Toxoplasma gondii, predominantly contains phosphatidylthreonine (PtdThr) over PS, showcasing the importance of PtdThr in parasite motility and virulence. While PS may not directly address seizures, its diverse roles in brain health, immunity, and cellular functions highlight its significance in various physiological processes.
What research fields is purified IL-1beta primarily used in?
5 answers
Purified IL-1beta is primarily used in various research fields such as cancer treatment and prevention with an inflammatory basis, understanding the fundamental role of inflammation in type 2 diabetes, particularly focusing on the contribution of IL-1beta, and in the treatment and prevention of auto-inflammatory syndromes like juvenile rheumatoid arthritis or adult rheumatoid arthritis syndrome in mammals, especially humans. IL-1beta is a crucial cytokine involved in immune cell activation, differentiation, and inflammatory responses, making it a valuable target for therapeutic interventions in conditions with inflammatory components. Its use spans across different areas of research, highlighting its significance in various disease processes and potential treatment strategies.
What is the theoretical model best describes nAChR on the plasma membrane?
5 answers
The theoretical model that best describes the nicotinic acetylcholine receptor (nAChR) on the plasma membrane involves a combination of atomistic and continuum electrostatics calculations, as proposed in one study. This model treats the pore-lining M2 helix bundle atomistically while representing the rest of the molecule as a "low resolution" cylinder with surface charge derived from the amino acid sequence. Additionally, the folding of the five polypeptide subunits into a functional structural model, where agonists control the opening and closing of the receptor, is crucial for understanding nAChR dynamics. Molecular dynamic simulations further contribute to investigating the conformation and function of nAChR models, shedding light on water molecules' roles and structural details like alternative conformations of specific residues. These combined approaches provide valuable insights into the structure and function of nAChRs on the plasma membrane.
What is the theoretical model best describes nAChR dynamics on the plasma membrane?
4 answers
The dynamics of nicotinic acetylcholine receptors (nAChRs) on the plasma membrane are best described by a model that considers various factors influencing receptor behavior. Molecular dynamics (MD) simulations have provided valuable insights into nAChR dynamics, highlighting asymmetrical motions of subunits, conformational shifts in the gate, and the role of lipid molecules in channel conformation. These simulations also reveal the impact of extracellular Ca2+ on nAChR structure and function, leading to partial channel opening and altered receptor conformation. Additionally, the mobility of nAChRs differs between muscle and neuronal receptors, with brain α7 nAChRs spending significant time peri-synaptically, influencing the balance between excitation and inhibition. Therefore, a comprehensive model incorporating these aspects of nAChR dynamics on the plasma membrane is essential for understanding receptor behavior.
Does glycine have an impact on luky guts syndrom?
5 answers
Glycine has been shown to have a significant impact on gut-related conditions such as inflammatory bowel disease (IBD), postoperative ileus, and nonalcoholic fatty liver disease (NAFLD). These studies highlight the role of glycine in regulating intestinal inflammation, immune responses, and gut microbiota composition. While the specific term "leaky gut syndrome" is not directly mentioned in the provided contexts, the overall findings suggest that glycine's anti-inflammatory and immunomodulatory properties could potentially benefit gut health conditions, including leaky gut syndrome. Glycine's ability to modulate immune responses, regulate inflammatory pathways, and influence gut microbiota balance may contribute to its potential positive effects on gut health. Further research specifically targeting leaky gut syndrome would be beneficial to fully understand the extent of glycine's impact on this condition.
What is the molecular mechanism behind eugenol's impact on the eye?
5 answers
Eugenol, a phenylpropanoid found in clove oil, exhibits diverse pharmacological activities. In the context of the eye, eugenol has been studied for its effects on fungal keratitis caused by Aspergillus fumigatus. Research shows that eugenol reduces keratitis severity, inflammatory responses, and fungal load by activating the Nrf2/HO-1 signaling pathway. Furthermore, eugenol's anti-inflammatory properties are linked to its ability to inhibit pro-inflammatory cytokines in human corneal epithelial cells. Additionally, eugenol's antifungal activity involves disrupting fungal membrane integrity and reducing ergosterol biosynthesis, thereby inhibiting A. fumigatus growth and adhesion to host cells. These findings suggest that eugenol's protective effects on the eye involve anti-inflammatory and antifungal mechanisms, making it a potential therapeutic agent for ocular conditions.
What did heidbreder say about rats and isolation?
4 answers
Heidbreder's research on rats and isolation revealed various behavioral and cognitive effects. Isolation rearing of rats led to increased aggressive interactions, hyperactivity, and nervousness. Additionally, isolated rats displayed impaired episodic memory and reduced ability to shift attention between stimulus dimensions, resembling cognitive deficits seen in schizophrenia. Social isolation also induced anxiogenic-like effects and increased the number of cholecystokinin (CCK) receptors in the frontal cortex of rats. Furthermore, isolation rearing heightened locomotor activity in response to a novel environment and increased sensitivity to the locomotor stimulant effects of cocaine. Interestingly, isolation-induced hyperactivity persisted even after rats were rehoused in social groups, highlighting lasting effects of early isolation.