If you have been reading about Nuclear receptor and want a single page that covers the useful parts, this is it: definitions, context, how it is studied, and the questions that come up repeatedly.
Last reviewed on 2026-05-13. Where a claim depends on a specific study, the study is described rather than over-claimed.
Handling and quality assessment of cardarine reference material follow general laboratory practices for poorly characterized compounds. It typically appears as a white to off-white powder and is sparingly soluble in water but soluble in organic solvents such as dimethyl sulfoxide and ethanol. Storage recommendations usually specify a cool, dry, dark place, with long-term storage at low temperature and desiccation. Purity may be checked by high-performance liquid chromatography with ultraviolet detection, while identity is confirmed by mass spectrometry and nuclear magnetic resonance. No pharmacopeial monograph exists, so reported purity and stability depend on the supplier’s methods.
GW501516 acts as a selective agonist at PPARδ, a nuclear receptor that regulates transcription of genes involved in lipid handling and energy metabolism. Activation of PPARδ in preclinical models increases fatty acid oxidation, mitochondrial biogenesis, and exercise endurance in rodents. These effects have made the compound a subject of metabolic research and also a target for sport anti-doping rules. In humans, however, controlled studies are limited, and whether similar endurance or metabolic changes occur at tolerated exposures remains an open question. The receptor’s broad tissue distribution also means downstream effects may vary by organ and condition.
Early clinical research explored GW501516 for lipid disorders, obesity, and diabetes. Some short-term human studies reported changes in HDL cholesterol, LDL cholesterol, and triglycerides. The development program was discontinued after rodent studies showed dose-dependent tumor formation in multiple tissues, including liver, bladder, stomach, and skin. These findings raised concerns about long-term cancer risk in humans. Because human exposure data are limited, the clinical significance of the rodent tumors remains uncertain.
Literature on cardarine often separates receptor pharmacology from toxicology. Mechanistic papers describe PPARδ activation and gene expression changes, while safety assessments focus on carcinogenicity and species differences. Questions remain about whether rodent tumors arise through PPARδ-dependent or off-target mechanisms. Another open area is how human metabolism and exposure compare with those in animal studies. Analytical methods such as liquid chromatography–mass spectrometry are used to confirm identity in biological and product samples.
GW501516 acts as an agonist at the peroxisome proliferator-activated receptor delta, a nuclear receptor that regulates gene expression. Activation shifts transcription toward genes involved in fatty acid uptake, oxidation, and energy expenditure. The compound does not bind the androgen receptor and therefore differs from anabolic steroids and SARMs. In rodent models, this metabolic shift has been linked to increased running endurance and reduced fat accumulation. The exact downstream pathways in humans remain incompletely characterized.
| Property | Value | Notes |
|---|---|---|
| Appearance | White to off-white powder | Visual description for typical solid reference material. |
| Solubility | Poorly soluble in water; soluble in DMSO | Solubility depends on solvent, purity, and form. |
| Storage | Cool, dry, protected from light | Long-term storage often uses low temperature and desiccant. |
| Common analytical method | LC-MS/MS | Used for detection and quantification in biological matrices. |
| Common synonyms | GW-501516; GW501516; endurobol | Naming varies among literature, vendors, and databases. |
Safety discussions about cardarine frequently cite rodent carcinogenicity findings reported in the 2000s. In those studies, treated animals developed tumors at multiple sites, leading sponsors to discontinue clinical development. The relevance of these findings to humans has not been resolved, but they are a major reason the compound is not approved. Current literature emphasizes uncertainty about long-term effects and the risks of unregulated use. Regulators and health agencies have not established a safe human exposure level.
Cardarine is a synthetic compound also known as GW501516, GW-501516, and sometimes endurobol. It was developed as a selective agonist of peroxisome proliferator-activated receptor delta, a nuclear receptor involved in fatty acid oxidation and energy metabolism. The compound was studied in preclinical models for metabolic and cardiovascular conditions, but it did not become a marketed human medicine. In regulatory and anti-doping contexts, it is treated as a prohibited substance rather than a licensed medicine.
Safety concerns emerged from long-term animal studies. In rodents given the compound for extended periods, researchers found an increased incidence of certain cancers, including liver and bladder tumors. These findings contributed to the discontinuation of clinical development. Whether similar risks apply to short-term or low-level exposure in humans is not established, and controlled human safety data are limited. The relevance of high-dose rodent carcinogenicity findings to human use remains a subject of debate.
Human trials of GW501516 were small and short in duration. They examined lipid levels, glucose handling, and other metabolic markers, but the programs were halted after the animal cancer findings. No approved therapeutic product exists, and published human data are insufficient for establishing long-term safety. Reports of use for athletic performance come mainly from non-clinical settings and cannot be verified through controlled trials. Independent testing of products sold as cardarine has found inconsistent purity and labeling.
Some MAAs protect cells from reactive oxygen species (i.e. singlet oxygen, superoxide anions, hydroperoxyl radicals, and hydroxyl radicals). Reactive oxygen species can be created during photosynthesis; further supporting the idea that MAAs provide protection from UV light. Mycosporine-glycine is a MAA that provides antioxidant protection even before Oxidative stress response genes and antioxidant enzymes are induced. MAA-glycine (mycosporine-glycine) is able to quench singlet oxygen and hydroxyl radicals very quickly and efficiently. Some oceanic microbial ecosystems are exposed to high concentrations of oxygen and intense light; these conditions are likely to generate high levels of reactive oxygen species. In these ecosystems, MAA-rich cyanobacteria may be providing antioxidant activity.
Currently, no over-the-counter weight-loss supplements have met criteria for recommended use by physicians. Dexatrim claims to provide a powerful benefit for weight loss despite the lack of scientific data to support their claims. Dexatrim further provides a disclaimer that no claims of efficacy and safety made by Dexatrim have been approved by the FDA. Although available OTC, the active ingredients in Dexatrim products carry risk of side effects, adverse reactions and adverse drug interactions, particularly if used at high-recommended or higher-than-recommended doses and/or for prolonged periods. The Dexatrim product itself carries a warning about the possible side effects of Dexatrim in patients with a history of high blood pressure, and also recommends the advice of a qualified physician before taking Dexatrim. In addition, the use of Dexatrim or other OTC weight-loss supplements presents a possible factor in establishing disruptive eating patterns, increases the risk that individuals will use these OTC supplements in lieu of seeking proper medical and nutritional consultation, and presents increased psychological risks associated with unsuccessful weight-loss attempts.
PHLPP is a member of the PPM family of phosphatases, which requires magnesium or manganese for their activity and are insensitive to most common phosphatase inhibitors, including [okadaic acid]. PHLPP1 and PHLPP2 have a similar domain structure, which includes a putative Ras association domain, a pleckstrin homology domain, a series of leucine-rich repeats, a PP2C phosphatase domain, and a C-terminal PDZ ligand. PHLPP1 has two splice variants, PHLPP1α and PHLPP1β, of which PHLPP1β is larger by approximately 1.5 kilobase pairs. PHLPP1α, which was the first PHLPP isoform to be characterized, lacks the N-terminal portion of the protein, including the Ras association domain. PHLPP's domain structure influences its ability to dephosphorylate its substrates. A PHLPP construct lacking the PH domain is unable to decrease PKC phosphorylation, while PHLPP lacking the PDZ ligand is unable to decrease Akt phosphorylation.
In this process, rare-earth ions are adsorbed onto suitable ion-exchange resin by exchange with hydrogen, ammonium or cupric ions present in the resin. Lutetium salts are then selectively washed out by suitable complexing agent. Lutetium metal is then obtained by reduction of anhydrous LuCl3 or LuF3 by either an alkali metal or alkaline earth metal.
Sources: en.wikipedia.org
Ghana possesses industrial minerals, hydrocarbons and precious metals. It is an emerging designated digital economy with mixed economy hybridisation and an emerging market. It has an economic plan target known as the "Ghana Vision 2020". This plan envisions Ghana as the first African country to become a developed country between 2020 and 2029 and a newly industrialised country between 2030 and 2039. This excludes fellow Group of 24 member and Sub-Saharan African country South Africa, which is a newly industrialised country. Ghana's economy has ties to the Chinese yuan renminbi along with Ghana's gold reserves. In 2013, the Bank of Ghana began circulating the renminbi throughout Ghanaian state-owned banks and to the Ghana public as hard currency along with the national Ghanaian cedi for second national trade currency. Between 2012 and 2013, 38% of rural dwellers were experiencing poverty whereas 11% of urban dwellers were. Urban areas hold greater opportunity for employment, particularly in informal trade, while 94% of "rural poor households" participate in the agricultural sector. The Volta River Authority and the Ghana National Petroleum Corporation, both state-owned, are the two major electricity producers. The Akosombo Dam, built on the Volta River in 1965, along with the Bui Dam, the Kpong Dam and other hydroelectric dams, provide hydropower.
== Examples == Morphine is the prototype of opioid analgesics Propranolol is the prototype of the beta blockers Chlorpromazine is the prototypical phenothiazine antipsychotic Imipramine is the prototypical tricyclic antidepressant, and itself a derivative of chlorpromazine Diazepam is the prototype of the benzodiazepine Diphenhydramine (Benadryl) is the prototype ethanolamine antihistamine Nifedipine is the prototype dihydropyridine calcium channel blocker Chloroquine is the prototypical antimalarial agent Acyclovir is the prototype antiviral agent that is activated by viral thymidine kinase Aspirin is the prototype NSAID Dextroamphetamine is the prototype Stimulant Omeprazole is the prototype Proton-pump inhibitor
HCTU is an amidinium coupling reagent used in peptide synthesis. It is analogous to HBTU. The HOBt moiety has a chlorine in the 6 position which improves reaction rates and the synthesis of difficult couplings HCTU and related reagents containing the 6-chloro-1-hydroxybenzotriazole moiety can be prepared by reaction with TCFH under basic conditions. It can exist in an N-form (guanidinium) or an O-form (uronium), but the N-form is generally considered to be more stable for this class of reagent. In vivo dermal sensitization studies according to OECD 429 confirmed HCTU is a strong skin sensitizer, showing a response at 0.50 wt% in the Local Lymph Node Assay (LLNA) placing it in Globally Harmonized System of Classification and Labelling of Chemicals (GHS) Dermal Sensitization Category 1A.
=== Preventing recreational opioid use === Naloxone is poorly absorbed when taken orally or sublingually, so it is often added to oral or sublingual opioid preparations, including buprenorphine and pentazocine, so that when swallowed or taken sublingually, only the non-naloxone opioid has an effect. However, if the combination is injected (such as by dissolving a pill or sublingual strip in water), the naloxone is believed to block the effect of the other opioid. This combination is used to prevent non-medical use. However, SAMHSA's clinical guidelines state that if the combination of buprenorphine and naloxone is injected by a regular user of buprenorphine or buprenorphine/naloxone, then the buprenorphine would still produce an agonist effect but the naloxone would fail to produce an antagonist effect. This is because the amount of naloxone that would be required to block the buprenorphine after injection is much larger than the amount that is contained in buprenorphine/naloxone (Suboxone) pills and strips. If someone who is not physically dependent on opioids were to inject the buprenorphine/naloxone combination, then the effects of the buprenorphine may at most be slightly lessened, but the individual would still be expected to experience euphoric effects.
== History == Polatuzumab vedotin was discovered by a team at Genentech led by Dan Eaton, Fred de Sauvage, and Andy Polson, who had been trying to develop ADCs for solid tumors without success, and in 2002 turned to blood cancers. In June 2019, polatuzumab vedotin was approved in the United States in combination with the chemotherapy bendamustine and a rituximab product, to treat adults with diffuse large B-cell lymphoma (DLBCL) that has progressed or returned after at least two prior therapies. Polatuzumab vedotin is a novel antibody-drug conjugate, and DLBCL is the most common type of non-Hodgkin lymphoma. The US Food and Drug Administration (FDA) granted accelerated approval to polatuzumab vedotin used in combination with the chemotherapy bendamustine and a rituximab product. The FDA approved polatuzumab vedotin based primarily on evidence from one clinical trial (NCT02257567) that was conducted in the United States, Canada, Europe, and Asia. Participants in the trial had lymphoma that came back or did not improve after prior treatment. The FDA granted the application of polatuzumab vedotin breakthrough therapy, priority review, and orphan drug designations. The FDA granted the approval of Polivy to Genentech. Polatuzumab vedotin was approved for medical use in the European Union in January 2020, as a second-line treatment. The European Medicines Agency (EMA) designated polatuzumab vedotin an orphan medicine in April 2018.
Sources: en.wikipedia.org
==== Digestive tract (emetic) ==== Serotonin regulates gastrointestinal (GI) function. The gut is surrounded by enterochromaffin cells, which release serotonin in response to food in the lumen. This makes the gut contract around the food. Platelets in the veins draining the gut collect excess serotonin. There are often serotonin abnormalities in gastrointestinal disorders such as constipation and irritable bowel syndrome. If irritants are present in the food, the enterochromaffin cells release more serotonin to make the gut move faster, i.e., to cause diarrhea, so the gut is emptied of the noxious substance. If serotonin is released in the blood faster than the platelets can absorb it, the level of free serotonin in the blood is increased. This activates 5-HT3 receptors in the chemoreceptor trigger zone that stimulate vomiting. Thus, drugs and toxins stimulate serotonin release from enterochromaffin cells in the gut wall which can induce emesis. The enterochromaffin cells not only react to bad food but are also very sensitive to irradiation and cancer chemotherapy. Drugs that block 5HT3 are very effective in controlling the nausea and vomiting produced by cancer treatment, and are considered the gold standard for this purpose.
=== Department stores === To manage its mail order business the department store Sears built "massive warehouses, like its central facility in Chicago, in which messages to various departments and assembly workers were sent through pneumatic tubes". Many other department stores had pneumatic tube systems in the 20th century, such as Jacksons of Reading and Myer in Melbourne, Australia. The National Library of Australia's building (opened 1968), incorporates a pneumatic tube system for sending book requests from the reading rooms to the book stacks. The system is no longer used, but remains partially operational, and is demonstrated on behind the scenes tours.
== Principle of operations == In peptide biosensors, peptides serve as the selective recognition element due to their amino acid sequence, which also accounts for their tailored binding affinity and specificity towards various analytes. When the analyte interacts with the peptide recognition elements via non-covalent interactions, this interaction produces a change that can be transduced into a measurable signal. Peptides on their own cannot generate a quantifiable signal after binding events with the analytes, they must be bio-conjugated to signal markers. Common detection strategies include optical methods such as fluorescence resonance energy transfer (FRET), electrochemical outputs such as change in current, impedance, or potential, and sometimes mechanical or piezoelectric signals if the peptide-analyte binding alters mass or surface properties. These methods are commonly employed due to their sensitivity and compatibility with small peptide-based interfaces
Brorphine is a piperidine-based opioid analgesic compound. Brorphine was originally described in a 2018 paper investigating functionally biased opioid compounds, with the intention of finding safer analgesics that produce less respiratory depression than typical opioids. Brorphine was originally reported to be highly biased, with an EC50 of 4.8nM for GTPγS binding and 182nM for β-arrestin recruitment, however a more recent study found no significant bias for any of the compounds tested, including brorphine. Its safety profile in any animal model has never been established. In a study involving human lymphoblastoid TK6 cells looking at the possible mutagenic effect of several orphine analogues, brophine was shown to have a marked cytostatic effect but no mutagenic properties. Despite the lack of safety information on the compound, brorphine has been sold as a designer drug since mid-2019, initially being identified in the US Midwest, though it has since been found in 2020 in Belgium. It is related in chemical structure to compounds such as benzylfentanyl and bezitramide, though it is sufficiently structurally distinct to fall outside the formal definition of a "fentanyl analogue" in jurisdictions such as the US and New Zealand which have Markush structure controls over this family of drugs. Despite its name, it is not a structural analog of morphine. Brorphine was first identified in the U.S.
Sources: en.wikipedia.org
Cardarine targets PPARδ, a nuclear receptor involved in lipid and energy metabolism. It does not bind the androgen receptor in the way SARMs do.
Most methods use liquid chromatography with tandem mass spectrometry. Urine is common in anti-doping testing, and blood or plasma may be used in research.
Typical guidance is cool, dry, dark storage, often at low temperature and with desiccant. Stability data are limited, so storage conditions should be verified for each batch or supplier.
It targets PPARδ, a nuclear receptor involved in lipid and energy metabolism. It does not act primarily on androgen receptors. This distinction separates it from SARMs.