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 during receptor upregulation?
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 of receptors?
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.
What happens during upregulation and downregulation?
In up-regulation, the number of receptors increases in response to rising hormone levels, making the cell more sensitive to the hormone and allowing for more cellular activity. When the number of receptors decreases in response to rising hormone levels, called down-regulation, cellular activity is reduced.
What does upregulate receptors mean?
In biology, the process by which a cell increases its response to a substance or signal from outside the cell to carry out a specific function. For example, a cell may increase the number or activity of protein receptors or other molecules on its surface to make it more sensitive to a hormone or drug.
What is the mechanism for receptor regulation?
Receptor regulation There are several mechanisms of such regulation: Increase or decrease of the number of receptor molecules expressed on the cell surface (or wherever the drug finds its targets) Increase or decrease of the concentration of downstream secondary messenger molecules (eg. cAMP)
What is the mechanism for up-regulation?
A mechanism for the increased or decreased sensitivity to agonists and antagonist drugs suggests that decreased exposure to an agonist results in an increase in the number of receptors (upregulation), while increased exposure to an agonist can result in a decrease in the number of receptors (downregulation).
What does it mean when a gene is upregulated?
(UP-reh-gyoo-LAY-shun) In biology, the process by which a cell increases its response to a substance or signal from outside the cell to carry out a specific function.
Why does up-regulation occur?
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.
What can cause upregulation of a target cell receptors quizlet?
the number of nuclei. Up-regulation of a target cell can occur in response to A. prolonged decrease in the level of a hormone.
What is cell upregulation?
Listen to pronunciation. (UP-reh-gyoo-LAY-shun) In biology, the process by which a cell increases its response to a substance or signal from outside the cell to carry out a specific function.
Do beta-blockers upregulate beta receptors?
There is an increase in the density of beta-adrenoceptors in the surface membrane, termed upregulation. This upregulation is subtype-specific, i.e., nonselective beta-blockers increase the density of both beta1- and beta2-adrenoceptors whereas beta1-selective antagonists upregulate only the former subtype.