Where does the upregulation of receptors occur?
Where does the upregulation of receptors occur?
Upregulation: An increase in the number of receptors on the surface of target cells, making the cells more sensitive to a hormone or another agent. For example, there is an increase in uterine oxytocin receptors in the third trimester of pregnancy, promoting the contraction of the smooth muscle of the uterus.
What is upregulation and downregulation in pharmacology?
In the biological context of organisms’ production of gene products, downregulation is the process by which a cell decreases the quantity of a cellular component, such as RNA or protein, in response to an external stimulus. The complementary process that involves increases of such components is called upregulation.
When does the downregulation of receptors occur?
Downregulation of adrenergic receptors in clinical conditions occurs within hours due to prolonged exposure to intrinsic (stress response) or extrinsic (vasopressor therapy) catecholamines and inflammatory mediators such as nitric oxide (NO), tumor necrosis factor, and other inflammatory cytokines (interleukin [IL]-1.
What causes upregulation receptors?
Numerous studies have shown that chronic exposure of a receptor to an antagonist typically leads to upregulation, or an increased number of receptors, while chronic exposure of a receptor to an agonist causes downregulation, or a decreased number of receptors (Creese & Sibley, 1981, Wonnacott, 1990).
What happens if there is downregulation of receptors?
Downregulation: An decrease in the number of receptors on the surface of target cells, making the cells less sensitive to a hormone or another agent. For example, insulin receptors may be downregulated in type 2 diabetes.
What causes up regulation?
Upregulation (i.e., increase in the number) of receptors occurs when the activity of the receptor is lower than usual (e.g., due to long-term administration of an antagonist). For example, administration of beta-blockers upregulates β adrenoreceptors.
Why does receptor upregulation occur?
What happens to the receptors when a drug is upregulated?
It occurs due to repeated or long-term administration of an agonist. Along with downregulation, desensitization of the receptor to the drug may also occur. This is a physicochemical alteration in the receptor which makes it unresponsive to the drug; this is also called tachyphylaxis and is seen in chronic drug use, for example.
What causes an increase in the number of receptors?
Together, PPARa and GR stimulation result in an enhanced response. Upregulation • Upregulation refers to an increase in the number of receptors due to prolonged deprivation of receptors of interacting with their physiological neurotransmitter (e.g. by denervation of chronic use of a receptor antagonist).
How does downregulation of receptors lead to Super sensitization?
Upregulation of receptors, on the other hand, can result in super-sensitized cells especially after repeated exposure to an antagonistic drug or prolonged absence of the ligand. Some receptor agonists may cause downregulation of their respective receptors, while most receptor antagonists temporarily upregulate their respective receptors.
How does upregulation occur in the human body?
Upregulation is a process that makes cells more responsive to stimuli like hormones by increasing the number of receptors on the surface of the cell. It occurs in response to environmental cues that can vary from changes in hormone levels associated with pregnancy to exposure to toxins.
