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Cirazoline
Cirazoline is a full agonist at the α1A adrenergic receptor, a partial agonist at both the α1B and α1D adrenergic receptors, and a nonselective antagonist to the α2 adrenergic receptor. It is believed that this combination of properties could make cirazoline an effective vasoconstricting agent. Cirazoline has also been shown to decrease food intake in rats, purportedly through activation of α1 adrenoceptors in the paraventricular nucleus The paraventricular nucleus (PVN, PVA, or PVH) is a nucleus in the hypothalamus. Anatomically, it is adjacent to the third ventricle and many of its neurons project to the posterior pituitary. These projecting neurons secrete oxytocin and a smaller ... in the hypothalamus of the brain.Administration of cirazoline also seemed to present impairment in the spatial memory of monkeys through the activation of the same receptors that showed decreased food intake in rats.However in preliminary studies, through stimulation of α2 adrenoceptors, w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alpha-2 Adrenergic Receptor
The alpha-2 (α2) adrenergic receptor (or adrenoceptor) is a G protein-coupled receptor (GPCR) associated with the Gi heterotrimeric G-protein. It consists of three highly homologous subtypes, including α2A-, α2B-, and α2C-adrenergic. Some species other than humans express a fourth α2D-adrenergic receptor as well. Catecholamines like norepinephrine (noradrenaline) and epinephrine (adrenaline) signal through the α2-adrenergic receptor in the central and peripheral nervous systems. Cellular localization The α2A adrenergic receptor is localised in the following central nervous system (CNS) structures: * Brainstem (especially the locus coeruleus) * Midbrain * Hypothalamus * Hippocampus * Spinal cord * Cerebral cortex * Cerebellum * Septum Whereas the α2B adrenergic receptor is localised in the following CNS structures: * Olfactory system * Thalamus * Pyramidal layer of the hippocampus * Cerebellar Purkinje layer and the α2C adrenergic receptor is localised in t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Agonist
An agonist is a chemical that activates a receptor to produce a biological response. Receptors are cellular proteins whose activation causes the cell to modify what it is currently doing. In contrast, an antagonist blocks the action of the agonist, while an inverse agonist causes an action opposite to that of the agonist. Etymology From the Greek αγωνιστής (agōnistēs), contestant; champion; rival < αγων (agōn), contest, combat; exertion, struggle < αγω (agō), I lead, lead towards, conduct; drive Types of agonists Receptors can be activated by either agonists (such as[...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alpha-1A Adrenergic Receptor
The alpha-1A adrenergic receptor (α1A adrenoreceptor), also known as ADRA1A, formerly known also as the alpha-1C adrenergic receptor, is an alpha-1 adrenergic receptor, and also denotes the human gene encoding it. There is no longer a subtype α1C receptor. At one time, there was a subtype known as α1C, but it was found to be identical to the previously discovered α1A receptor subtype. To avoid confusion, the naming convention was continued with the letter D. Receptor There are 3 alpha-1 adrenergic receptor subtypes: alpha-1A, -1B and -1D, all of which signal through the Gq/11 family of G-proteins. Different subtypes show different patterns of activation. The majority of alpha-1 receptors are directed toward the function of epinephrine, a hormone that has to do with the fight-or-flight response. Gene This gene encodes the alpha-1A-adrenergic receptor. Alternative splicing of this gene generates four transcript variants, which encode four different isoforms with distinct C-te ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Partial Agonist
In pharmacology, partial agonists are drugs that bind to and activate a given receptor, but have only partial efficacy at the receptor relative to a full agonist. They may also be considered ligands which display both agonistic and antagonistic effects—when both a full agonist and partial agonist are present, the partial agonist actually acts as a competitive antagonist , competing with the full agonist for receptor occupancy and producing a net decrease in the receptor activation observed with the full agonist alone. Clinically, partial agonists can be used to activate receptors to give a desired submaximal response when inadequate amounts of the endogenous ligand are present, or they can reduce the overstimulation of receptors when excess amounts of the endogenous ligand are present. Some currently common drugs that have been classed as partial agonists at particular receptors include buspirone, aripiprazole, buprenorphine, nalmefene and norclozapine. Examples of ligan ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alpha-1B Adrenergic Receptor
The alpha-1B adrenergic receptor (α1B-adrenoreceptor), also known as ADRA1B, is an alpha-1 adrenergic receptor, and also denotes the human gene encoding it. The crystal structure of the α1B-adrenergic receptor has been determined in complex with the inverse agonist (+)-cyclazosin. Receptor There are 3 alpha-1 adrenergic receptor subtypes: alpha-1A, -1B and -1D, all of which signal through the Gq/11 family of G-proteins and different subtypes show different patterns of activation. They activate mitogenic responses and regulate growth and proliferation of many cells. Gene This gene encodes alpha-1B-adrenergic receptor, which induces neoplastic transformation when transfected into NIH 3T3 fibroblasts and other cell lines. Thus, this normal cellular gene is identified as a protooncogene. This gene comprises 2 exons and a single large intron of at least 20 kb that interrupts the coding region. Ligands ; Antagonists * L-765,314 * Risperidone * Brexpiprazole Interactions Alpha-1B adr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alpha-1D Adrenergic Receptor
The alpha-1D adrenergic receptor (α1D adrenoreceptor), also known as ADRA1D, is an alpha-1 adrenergic receptor, and also denotes the human gene encoding it. Receptor There are 3 alpha-1 adrenergic receptor subtypes: alpha-1A, -1B and -1D, all of which signal through the Gq/11 family of G-proteins and different subtypes show different patterns of activation. They activate mitogenic responses and regulate growth and proliferation of many cells. Gene This gene encodes alpha-1D-adrenergic receptor. Similar to alpha-1B-adrenergic receptor gene, this gene comprises 2 exons and a single intron that interrupts the coding region. Ligands ; Antagonists * A-315456 * BMY 7378 (also α2C antagonist) See also *Adrenergic receptor The adrenergic receptors or adrenoceptors are a class of G protein-coupled receptors that are targets of many catecholamines like norepinephrine (noradrenaline) and epinephrine (adrenaline) produced by the body, but also many medications like beta ... Reference ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Antagonist
An antagonist is a character in a story who is presented as the chief foe of the protagonist. Etymology The English word antagonist comes from the Greek ἀνταγωνιστής – ''antagonistēs'', "opponent, competitor, villain, enemy, rival," which is derived from ''anti-'' ("against") and ''agonizesthai'' ("to contend for a prize"). Types Heroes and villains The antagonist is commonly positioned against the protagonist and their world order. While most narratives will often portray the protagonist as a hero and the antagonist as a villain, like Harry Potter and Lord Voldemort in ''Harry Potter'', the antagonist does not always appear as the villain. In some narratives, like Light Yagami and L in ''Death Note'', the protagonist is a villain and the antagonist is an opposing hero. Antagonists are conventionally presented as making moral choices less savory than those of protagonists. This condition is often used by an author to create conflict within a story. This i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vasoconstriction
Vasoconstriction is the narrowing of the blood vessels resulting from contraction of the muscular wall of the vessels, in particular the large arteries and small arterioles. The process is the opposite of vasodilation, the widening of blood vessels. The process is particularly important in controlling hemorrhage and reducing acute blood loss. When blood vessels constrict, the flow of blood is restricted or decreased, thus retaining body heat or increasing vascular resistance. This makes the skin turn paler because less blood reaches the surface, reducing the radiation of heat. On a larger level, vasoconstriction is one mechanism by which the body regulates and maintains mean arterial pressure. Medications causing vasoconstriction, also known as vasoconstrictors, are one type of medicine used to raise blood pressure. Generalized vasoconstriction usually results in an increase in systemic blood pressure, but it may also occur in specific tissues, causing a localized reducti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Paraventricular Nucleus
The paraventricular nucleus (PVN, PVA, or PVH) is a nucleus in the hypothalamus. Anatomically, it is adjacent to the third ventricle and many of its neurons project to the posterior pituitary. These projecting neurons secrete oxytocin and a smaller amount of vasopressin, otherwise the nucleus also secretes corticotropin-releasing hormone (CRH) and thyrotropin-releasing hormone (TRH). CRH and TRH are secreted into the hypophyseal portal system and act on different targets neurons in the anterior pituitary. PVN is thought to mediate many diverse functions through these different hormones, including osmoregulation, appetite, and the response of the body to stress. Location The paraventricular nucleus lies adjacent to the third ventricle. It lies within the periventricular zone and is not to be confused with the periventricular nucleus, which occupies a more medial position, beneath the third ventricle. The PVN is highly vascularised and is protected by the blood–brain bar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alpha-1 Adrenergic Receptor Agonists
Alpha 1 or Alpha-1 may refer to: *Alpha-1 adrenergic receptor, a G protein-coupled receptor *Alpha-1 antitrypsin, a protein **Alpha-1 antitrypsin deficiency, a genetic disorder * Alpha-1-fetoprotein or Alpha-fetoprotein, a protein *Alpha-One, a fictional spacecraft in '' Buzz Lightyear of Star Command: The Adventure Begins'' * ''Alpha 1'' (Robert Silverberg anthology), a 1970 book See also * * *Alpha (other) *AMY1A Alpha-amylase 1 is an enzyme that in humans is encoded by the ''AMY1A'' gene. This gene is found in many organisms. Amylases are secreted proteins that hydrolyze 1,4-alpha-glucoside bonds in oligosaccharides and polysaccharides, and thus catalyze ... or Alpha-1A or, an enzyme found in humans and other mammals * List of A1 genes, proteins or receptors {{disambiguation ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cyclopropyl Compounds
A cyclopropyl group is a chemical structure derived from cyclopropane, and can participate in organic reactions that constitute cycloadditions and rearrangement organic reactions of cyclopropane. The group has an empirical formula of C3H5 and chemical bond A chemical bond is a lasting attraction between atoms or ions that enables the formation of molecules and crystals. The bond may result from the electrostatic force between oppositely charged ions as in ionic bonds, or through the sharing o ...s from each of the three carbons to both of the other two. Structure and bonding Due to the unfavoured bond angles (60°), cyclopropyl groups are highly strained. Two orbital models were proposed to describe the bonding situation. The Coulson-Moffit model uses bent bonds. The C-C bonds are formed by overlap of two sp-hybrid orbitals. To adapt to the small bond angle, there is some rehybridization resulting in sp~5-hybrids for the ring bonds and sp~2 for the C-H bonds. This model ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
