Prostaglandin in the context of "Arachidonic acid"

Abortion is the termination of a pregnancy by removal or expulsion of an embryo or fetus. The unmodified word abortion generally refers to induced abortion, or deliberate actions to end a pregnancy. Abortion occurring without intervention is known as spontaneous abortion or "miscarriage", and occurs in roughly 30–40% of all pregnancies. Common reasons for inducing an abortion are birth-timing and limiting family size. Other reasons include maternal health, an inability to afford a child, domestic violence, lack of support, feelings of being too young, wishing to complete an education or advance a career, and not being able, or willing, to raise a child conceived as a result of rape or incest.

When done legally in industrialized societies, induced abortion is one of the safest procedures in medicine. Modern methods use medication or surgery for abortions. The drug mifepristone (aka RU-486) in combination with prostaglandin appears to be as safe and effective as surgery during the first and second trimesters of pregnancy. Self-managed medication abortion is highly effective and safe throughout the first trimester. The most common surgical technique involves dilating the cervix and using a suction device. Birth control, such as the pill or intrauterine devices, can be used immediately following an abortion. When performed legally and safely on a woman who desires it, an induced abortion does not increase the risk of long-term mental or physical problems. In contrast, unsafe abortions performed by unskilled individuals, with hazardous equipment, or in unsanitary facilities cause between 22,000 and 44,000 deaths and 6.9 million hospital admissions each year — responsible for between 5% and 13% of maternal deaths, especially in low-income countries. The World Health Organization states that "access to legal, safe and comprehensive abortion care, including post-abortion care, is essential for the attainment of the highest possible level of sexual and reproductive health". Public health data show that making safe abortion legal and accessible reduces maternal deaths.

A hormone (from the Greek participle ὁρμῶν, "setting in motion") is a class of signaling molecules in multicellular organisms that are sent to distant organs or tissues by complex biological processes to regulate physiology and behavior. Hormones are required for the normal development of animals, plants and fungi. Due to the broad definition of a hormone (as a signaling molecule that exerts its effects far from its site of production), numerous kinds of molecules can be classified as hormones. Among the substances that can be considered hormones, are eicosanoids (e.g. prostaglandins and thromboxanes), steroids (e.g. oestrogen and brassinosteroid), amino acid derivatives (e.g. epinephrine and auxin), protein or peptides (e.g. insulin and CLE peptides), and gases (e.g. ethylene and nitric oxide).

Hormones are used to communicate between organs and tissues. In vertebrates, hormones are responsible for regulating a wide range of processes including both physiological processes and behavioral activities such as digestion, metabolism, respiration, sensory perception, sleep, excretion, lactation, stress induction, growth and development, movement, reproduction, and mood manipulation. In plants, hormones modulate almost all aspects of development, from germination to senescence.

Misoprostol is a synthetic prostaglandin medication used to prevent and treat stomach and duodenal ulcers, induce labor, cause an abortion, and treat postpartum bleeding due to poor contraction of the uterus. It is taken by mouth when used to prevent gastric ulcers in people taking nonsteroidal anti-inflammatory drugs (NSAID). For abortions it is typically used in conjunction with mifepristone or methotrexate, but can be used alone. By itself, effectiveness for abortion is between 82% and 100%. Its efficacy with mifepristone is higher, but varies based on gestational age. The misoprostol-only abortion regimen is typically recommended only when mifepristone is not available. For labor induction or abortion, it is taken by mouth, dissolved in the mouth, or placed in the vagina. For postpartum bleeding it may also be used rectally.

Common side effects include diarrhea and abdominal pain. It is in pregnancy category X, meaning that it is known to result in negative outcomes for the fetus if taken during pregnancy. In rare cases, uterine rupture may occur. It is a prostaglandin analogue—specifically, a synthetic prostaglandin E₁ (PGE₁).

Eicosanoids are signaling molecules made by the enzymatic or non-enzymatic oxidation of arachidonic acid or other polyunsaturated fatty acids (PUFAs) that are, similar to arachidonic acid, around 20 carbon units in length. Eicosanoids are a sub-category of oxylipins, i.e. oxidized fatty acids of diverse carbon units in length, and are distinguished from other oxylipins by their overwhelming importance as cell signaling molecules. Eicosanoids function in diverse physiological systems and pathological processes such as: mounting or inhibiting inflammation, allergy, fever and other immune responses; regulating the abortion of pregnancy and normal childbirth; contributing to the perception of pain; regulating cell growth; controlling blood pressure; and modulating the regional flow of blood to tissues. In performing these roles, eicosanoids most often act as autocrine signaling agents to impact their cells of origin or as paracrine signaling agents to impact cells in the proximity of their cells of origin. Some eicosanoids, such as prostaglandins, may also have endocrine roles as hormones to influence the function of distant cells.

There are multiple subfamilies of eicosanoids, including most prominently the prostaglandins, thromboxanes, leukotrienes, lipoxins, resolvins, and eoxins. For each subfamily, there is the potential to have at least 4 separate series of metabolites, two series derived from the ω−6 PUFAs arachidonic and dihomo-gamma-linolenic acids, one series derived from the ω−3 PUFA eicosapentaenoic acid, and one series derived from the ω−9 PUFA mead acid. This subfamily distinction is important. Mammals, including humans, are unable to convert ω−6 into ω−3 PUFA. In consequence, tissue levels of the ω−6 and ω−3 PUFAs and their corresponding eicosanoid metabolites link directly to the amount of dietary ω−6 versus ω−3 PUFAs consumed. Since certain of the ω−6 and ω−3 PUFA series of metabolites have almost diametrically opposing physiological and pathological activities, it has often been suggested that the deleterious consequences associated with the consumption of ω−6 PUFA-rich diets reflects excessive production and activities of ω−6 PUFA-derived eicosanoids, while the beneficial effects associated with the consumption of ω−3 PUFA-rich diets reflect the excessive production and activities of ω−3 PUFA-derived eicosanoids. In this view, the opposing effects of ω−6 PUFA-derived and ω−3 PUFA-derived eicosanoids on key target cells underlie the detrimental and beneficial effects of ω−6 and ω−3 PUFA-rich diets on inflammation and allergy reactions, atherosclerosis, hypertension, cancer growth, and a host of other processes.

In molecular biology, prostanoids are active lipid mediators that regulate inflammatory response. Prostanoids are a subclass of eicosanoids consisting of the prostaglandins (mediators of inflammatory and anaphylactic reactions), the thromboxanes (mediators of vasoconstriction), and the prostacyclins (active in the resolution phase of inflammation). Prostanoids are seen to target NSAIDS which allow for therapeutic potential. Prostanoids are present within areas of the body such as the gastrointestinal tract, urinary tract, respiratory and cardiovascular systems, reproductive tract and vascular system. Prostanoids can even be seen with aid to the water and ion transportation within cells.

Prostaglandin E₁ (PGE₁) is a naturally occurring prostaglandin with various medical uses. Alprostadil and misoprostol are synthetic forms of prostaglandin E1 used as medications. Lubiprostone, a derivative of prostaglandin E1, is also used as a medication. Prostaglandin E₁ is a vasodilator. It has various effects in the body that include opening blood vessels, relaxing smooth muscle, inhibiting clotting, and causing uterine contractions.

In infants with certain congenital heart defects, alprostadil is delivered by slow injection into a vein to maintain a patent ductus arteriosus until surgery can be carried out. By injection into the penis or placement in the urethra, alprostadil is used to treat erectile dysfunction. Common side effects when given to babies include decreased breathing, fever, and low blood pressure. When injected into the penis for erectile dysfunction; side effects may include penile pain, bleeding at the site of injection, and prolonged erection (priapism). Prostaglandin E₁ was isolated in 1957 and approved for medical use in the United States in 1981.

Labor induction is the procedure where a medical professional starts the process of labor (giving birth) instead of letting it start on its own. Labor may be induced (started) if the health of the mother or the baby is at risk. Induction of labor can be accomplished with pharmaceutical or non-pharmaceutical methods.

In Western countries, it is estimated that one-quarter of pregnant women have their labor medically induced with drug treatment. Inductions are most often performed either with prostaglandin drug treatment alone, or with a combination of prostaglandin and intravenous oxytocin treatment.