Why are nuclear receptors good drug targets?
Nuclear receptors (NRs) are ideal targets for drug discovery. Not only do they control a myriad of biological and disease processes, but they are also regulated by small lipophilic molecules that can be easily exchanged with a drug of choice.
What drug acts on nuclear receptors?
Nuclear Hormone Receptors/NHRs as Drug Target Table
|Farnesoid X receptor||NR1H4||bile acids|
|Vitamin D receptor||VDR||vitamin D|
|Pregnane X receptor||NR1I2||xenobiotics|
|Constitutive androstane receptor||NR1I3||xenobiotics|
What drugs cause Tachyphylaxis?
Over-the-counter ophthalmic decongestant drops, such as Visine (Pfizer), are another category of drugs that induce tachyphylaxis. In particular, these medications contain alpha-adrenergic amines—such as tetrahydrozoline, naphazoline or phenylephrine—that act as vasoconstrictors.
How does a nuclear receptor work?
Nuclear receptors are activated by lipid-soluble signals (e.g., steroid hormones) that cross the plasma membrane. Once activated, most function as transcription factors to control gene expression for numerous biological processes.
When two drug act on the same receptor The resulting drug interaction is said to be which of the following?
From a pharmacodynamic perspective, two drugs can be considered to be: Homodynamic, if they act on the same receptor. They, in turn, can be: Pure agonists, if they bind to the main locus of the receptor, causing a similar effect to that of the main drug.
What does drug tachyphylaxis mean?
Tachyphylaxis is the loss of response of tissues following repeated or continuous administration of a drug.
What is drug tachyphylaxis?
Tachyphylaxis is defined as a rapidly decreasing response to a drug following its initial administration. This decreased drug sensitivity, like the placebo effect, can occur with any drug.
What is the meaning of nuclear receptor?
Nuclear receptors (NRs) are transcription factors that regulate a myriad of biological processes, including cell growth and development, metabolism, reproduction and inflammation (Evans, 2005; Laudet, 1997).
How many functions do nuclear receptors have?
Nuclear receptors consist of up to four domains that fulfill different modular functions (Figure 1). The C-domain, also referred to as DNA-binding domain (DBD) is stabilized by two zinc fingers, necessary for identification and binding to specific response elements in the DNA (Kumar and Thompson, 1999).
How do drugs interact with their targets?
By sharing a pair of electrons, a new molecule is formed via a covalent interaction. The interaction is very strong, leading to irreversible binding between a drug and its target. This usually results in a sustained biological effect that cannot be altered.
What are the different forces involved in drug receptor interaction give 1 example each?
Drugs interact with receptors by means of chemical bonds. The three major types of bonds are covalent, electrostatic, and hydrophobic. Covalent bonds are strong and, in many cases, not reversible under biologic conditions. Electrostatic bonds are weaker than covalent bonds, more common, and often reversible.
What is the difference between tachyphylaxis and tolerance?
The term tachyphylaxis is used to describe desensitization that occurs very rapidly, sometimes with the initial dose. The term tolerance is conventionally used to describe a more gradual loss of response to a drug that occurs over days or weeks.