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Vasoactive
A vasoactive substance is an endogenous agent or pharmaceutical drug that has the effect of either increasing or decreasing blood pressure and/or heart rate through its vasoactivity, that is, vascular activity (effect on blood vessels). By adjusting vascular compliance and vascular resistance, typically through vasodilation and vasoconstriction, it helps the body's homeostatic mechanisms (such as the renin–angiotensin system) to keep hemodynamics under control. For example, angiotensin, bradykinin, histamine, nitric oxide, and vasoactive intestinal peptide are important endogenous vasoactive substances. Vasoactive drug therapy is typically used when a patient has the blood pressure and heart rate monitored constantly. The dosage is typically titrated (adjusted up or down) to achieve a desired effect or range of values as determined by competent clinicians. Vasoactive drugs are typically administered using a volumetric infusion device (IV pump). This category of drugs requi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vasoactive Intestinal Peptide
Vasoactive intestinal peptide, also known as vasoactive intestinal polypeptide or VIP, is a peptide hormone that is vasoactive in the intestine. VIP is a peptide of 28 amino acid residue (chemistry), residues that belongs to a Secretin family, glucagon/secretin superfamily, the ligand (biochemistry), ligand of class II G protein–coupled receptors. VIP is produced in many tissues of vertebrates including the Gut (zoology), gut, pancreas, neocortex, and suprachiasmatic nuclei of the hypothalamus in the brain. VIP stimulates contractility in the heart, causes vasodilation, increases glycogenolysis, lowers arterial blood pressure and relaxes the smooth muscle of Vertebrate trachea, trachea, stomach and gallbladder. In humans, the vasoactive intestinal peptide is encoded by the ''VIP'' gene. VIP has a half-life (t½) in the blood of about two minutes. Function In the digestive system In the digestive system, VIP seems to induce smooth muscle relaxation (lower esophageal sphincte ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Compliance (physiology)
Compliance is the ability of a hollow organ (vessel) to distend and increase volume with increasing transmural pressure or the tendency of a hollow organ to resist recoil toward its original dimensions on application of a distending or compressing force. The reciprocal of compliance is elastance, a measure of the tendency of a hollow organ to recoil toward its original dimensions upon removal of a distending or compressing force. Blood vessels The terms elastance and compliance are of particular significance in cardiovascular physiology and respiratory physiology. In compliance, an increase in volume occurs in a vessel when the pressure in that vessel is increased. The tendency of the arteries and veins to stretch in response to pressure has a large effect on perfusion and blood pressure. This physically means that blood vessels with a higher compliance deform easier than lower compliance blood vessels under the same pressure and volume conditions. Venous compliance is approximate ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Blood Pressure
Blood pressure (BP) is the pressure of Circulatory system, circulating blood against the walls of blood vessels. Most of this pressure results from the heart pumping blood through the circulatory system. When used without qualification, the term "blood pressure" refers to the pressure in a brachial artery, where it is most commonly measured. Blood pressure is usually expressed in terms of the systolic pressure (maximum pressure during one Cardiac cycle, heartbeat) over diastolic pressure (minimum pressure between two heartbeats) in the cardiac cycle. It is measured in Millimetre of mercury, millimetres of mercury (mmHg) above the surrounding atmospheric pressure, or in Pascal (unit), kilopascals (kPa). The difference between the systolic and diastolic pressures is known as pulse pressure, while the average pressure during a cardiac cycle is known as mean arterial pressure. Blood pressure is one of the vital signs—together with respiratory rate, heart rate, Oxygen saturation (me ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Histamine
Histamine is an organic nitrogenous compound involved in local immune responses communication, as well as regulating physiological functions in the gut and acting as a neurotransmitter for the brain, spinal cord, and uterus. Discovered in 1910, histamine has been considered a local hormone ( autocoid) because it is produced without involvement of the classic endocrine glands; however, in recent years, histamine has been recognized as a central neurotransmitter. Histamine is involved in the inflammatory response and has a central role as a mediator of itching. As part of an immune response to foreign pathogens, histamine is produced by basophils and by mast cells found in nearby connective tissues. Histamine increases the permeability of the capillaries to white blood cells and some proteins, to allow them to engage pathogens in the infected tissues. It consists of an imidazole ring attached to an ethylamine chain; under physiological conditions, the amino grou ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Prostanoid
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. History Prostanoids were discovered through biological research studies conducted in the 1930s. The first discovery was seen through semen by a Swedish Physiologist Ulf von Euler, who assumed they originated from the prostate. After intensive study throughout the 1960-1970s Sune K. Bergstr� ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Drug
A drug is any chemical substance other than a nutrient or an essential dietary ingredient, which, when administered to a living organism, produces a biological effect. Consumption of drugs can be via insufflation (medicine), inhalation, drug injection, injection, smoking, ingestion, absorption (skin), absorption via a dermal patch, patch on the skin, suppository, or sublingual administration, dissolution under the tongue. In pharmacology, a drug is a chemical substance, typically of known structure, which, when administered to a living organism, produces a biological effect. A pharmaceutical drug, also called a medication or medicine, is a chemical substance used to pharmacotherapy, treat, cure, preventive healthcare, prevent, or medical diagnosis, diagnose a disease or to promote well-being. Traditionally drugs were obtained through extraction from medicinal plants, but more recently also by organic synthesis. Pharmaceutical drugs may be used for a limited duration, or on a re ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Clinician
A clinician is a health care professional typically employed at a skilled nursing facility or clinic. Clinicians work directly with patients rather than in a laboratory, community health setting or in research. A clinician may diagnose, treat and care for patients as a psychologist, clinical pharmacist, clinical scientist, nurse, occupational therapist, speech-language pathologist, physiotherapist, dentist, optometrist, physician assistant, clinical officer, physician, paramedic, or chaplain. Clinicians undergo and take comprehensive training and exams to be licensed and some complete graduate degrees (master's or doctorates) in their field of expertise. The main function of a clinician is to manage a sick person in order to cure their illness, reduce pain and suffering, and extend life considering the impact of illness upon the patient and their family as well as other social factors. See also * List of healthcare occupations A listing of health care professions by m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Endothelin
Endothelins are peptides with receptors and effects in many body organs. Endothelin constricts blood vessels and raises blood pressure. The endothelins are normally kept in balance by other mechanisms, but when overexpressed, they contribute to high blood pressure (hypertension), heart disease, and potentially other diseases. Endothelins are 21-amino acid vasoconstricting peptides produced primarily in the endothelium having a key role in vascular homeostasis. Endothelins are implicated in vascular diseases of several organ systems, including the heart, lungs, kidneys, and brain. As of 2018, endothelins remain under extensive basic and clinical research to define their roles in several organ systems. Etymology Endothelins derived the name from their isolation in cultured endothelial cells. Isoforms There are three isoforms of the peptide (identified as ET-1, 2, 3), each encoded by a separate gene, with varying regions of expression and binding to at least four known e ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Adrenergic Agonist
An adrenergic agonist is a drug that stimulates a response from the adrenergic receptors. The five main categories of adrenergic receptors are: α1, α2, β1, β2, and β3, although there are more subtypes, and agonists vary in specificity between these receptors, and may be classified respectively. However, there are also other mechanisms of adrenergic agonism. Epinephrine and norepinephrine are endogenous and broad-spectrum. More selective agonists are more useful in pharmacology. An ' agent is a drug, or other substance, which has effects similar to, or the same as, epinephrine (adrenaline). Thus, it is a kind of sympathomimetic agent. Alternatively, it may refer to something which is susceptible to epinephrine, or similar substances, such as a biological receptor (specifically, the adrenergic receptors). Receptors Directly acting adrenergic agonists act on adrenergic receptors. All adrenergic receptors are G-protein coupled, activating signal transduction pathways. The G-prot ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pulmonary Arterial Hypertension
Pulmonary arterial hypertension (PAH) is a syndrome in which the blood pressure in the pulmonary arteries and pulmonary arterioles (the blood vessels located proximal to the capillary bed, the site of oxygen exchange in the lungs) is elevated. This pre-capillary pulmonary artery pressure being elevated is essential, and by definition a mean pulmonary artery pressure greater than 20 mmHg as measured by a right heart catheterization is required for the diagnosis. This pre-capillary pulmonary hypertension is confirmed with measuring pulmonary vascular resistance being greater than 3 Woods Units. A pulmonary artery wedge pressure being less than 15 mmHg (also measured by right heart catheterization) excludes post-capillary bed (in the veins distal to the capillary bed) pulmonary hypertension. Pulmonary arterial hypertension is a subgroup of pulmonary hypertension and is categorized as World Health Organization as group 1. PAH is further subdivided into various categories based on t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phosphodiesterase Inhibitor
A phosphodiesterase inhibitor is a drug that blocks one or more of the five subtypes of the enzyme phosphodiesterase (PDE), thereby preventing the inactivation of the intracellular second messengers, cyclic adenosine monophosphate (cAMP) and cyclic guanosine monophosphate (cGMP) by the respective PDE subtype(s). The ubiquitous presence of this enzyme means that non-specific inhibitors have a wide range of actions, with those in the heart and lungs being some of the first to find therapeutic use. History The different forms or subtypes of phosphodiesterase were initially isolated from rat brains in the early 1970s and were soon afterward shown to be selectively inhibited in the brain and in other tissues by a variety of drugs. The potential for selective phosphodiesterase inhibitors as therapeutic agents was predicted as early as 1977 by Weiss and Hait. This prediction meanwhile has proved to be true in a variety of fields. Classification Nonselective PDE inhibitors Methylated ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dose (biochemistry)
A dose is a measured quantity of a medicine, nutrient, or pathogen that is delivered as a unit. The greater the quantity delivered, the larger the dose. Doses are most commonly measured for compounds in medicine. The term is usually applied to the quantity of a drug or other agent administered for therapeutic purposes, but may be used to describe any case where a substance is introduced to the body. In nutrition, the term is usually applied to how much of a specific nutrient is in a person's diet or in a particular food, meal, or dietary supplement. For bacterial or Virus, viral agents, dose typically refers to the amount of the pathogen required to infect a host. In clinical pharmacology, ''dose'' refers to the amount of drug administered to a person, and Dosage (pharmacology), ''dosage'' is a fuller description that includes not only the dose (e.g., "500 mg") but also the frequency and duration of the treatment (e.g., "twice a day for one week"). Exposure assessment, '' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
