Mrs.

Mrs. (American English) or Mrs (British English) (Standard English pronunciation /ˈmɪsᵻz/) is a commonly used English honorific used for women, usually for those who are married and who do not instead use another title (or rank), such as Dr, Professor, Ms., President, Dame, Prime Minister, etc. In most Commonwealth countries, a full stop (period) is not used with the title. In the United States and Canada a period is used (see Abbreviation).

Mrs originated as a contraction of the honorific Mistress, the feminine of Mister, or Master, which was originally applied to both married and unmarried women. The split into Mrs for married women and Miss for unmarried began during the 17th century; the 20th century saw the coinage of a new unmarked option Ms.

It is rare for Mrs to be written in a non-abbreviated form, and the unabbreviated word lacks a standard spelling. In literature it may appear as missus or missis in dialogue. A variant in the works of Thomas Hardy and others is "Mis'ess", reflecting its etymology. Misses has been used but is ambiguous, as this is a commonly-used plural for Miss.

MRS

MRS, Mrs, or mrs can refer to:

Adenosine receptor

The adenosine receptors (or P1 receptors) are a class of purinergic G protein-coupled receptors with adenosine as endogenous ligand.

Pharmacology

In humans, there are four types of adenosine receptors. Each is encoded by a separate gene and has different functions, although with some overlap. For instance, both A₁ receptors and A_2A play roles in the heart, regulating myocardial oxygen consumption and coronary blood flow, while the A_2A receptor also has broader anti-inflammatory effects throughout the body. These two receptors also have important roles in the brain, regulating the release of other neurotransmitters such as dopamine and glutamate, while the A_2B and A₃ receptors are located mainly peripherally and are involved in processes such as inflammation and immune responses.

Most older compounds acting on adenosine receptors are nonselective, with the endogenous agonist adenosine being used in hospitals as treatment for severe tachycardia (rapid heart beat), and acting directly to slow the heart through action on all four adenosine receptors in heart tissue, as well as producing a sedative effect through action on A₁ and A_2A receptors in the brain. Xanthine derivatives such as caffeine and theophylline act as non-selective antagonists at A₁ and A_2A receptors in both heart and brain and so have the opposite effect to adenosine, producing a stimulant effect and rapid heart rate. These compounds also act as phosphodiesterase inhibitors, which produces additional anti-inflammatory effects, and makes them medically useful for the treatment of conditions such as asthma, but less suitable for use in scientific research.