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.
Updated 2025-12-09. Numbers and descriptions here follow the published literature rather than marketing material.
Cardarine is a common name for GW501516, a synthetic compound developed in the 1990s through research collaborations involving GlaxoSmithKline. It belongs to a class of molecules known as peroxisome proliferator-activated receptor delta agonists. Early studies explored its effects on lipid metabolism and energy expenditure in animal models. The compound was never approved as a human medicine, and clinical development was discontinued. In the years since, it has appeared in fitness and bodybuilding communities as a performance-enhancing substance. Regulatory agencies classify it as an unapproved drug.
PPARδ is a nuclear receptor that regulates gene expression related to fatty acid oxidation, glucose homeostasis, and mitochondrial function. GW501516 binds to this receptor with high affinity and activates downstream signaling in skeletal muscle and other tissues. Animal studies reported increased endurance and altered fuel preference, but human data remain limited and inconsistent. The precise relationship between receptor activation and observed physiological changes is still an area of active investigation. Researchers have also examined whether the compound affects inflammation or cell proliferation. No approved therapeutic indication exists for cardarine.
In laboratory settings, cardarine is studied as a tool compound for probing PPARδ biology. Published experiments often use cell cultures, rodent models, or isolated tissues. Some investigations focus on metabolic effects, while others assess potential risks such as carcinogenicity observed in long-term animal studies. Because human trials are sparse, most knowledge comes from preclinical work and adverse event reports. Scientific literature frequently notes the gap between animal findings and human outcomes. The compound is not a dietary supplement and is not intended for human consumption.
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.
Detection of GW501516 in biological samples generally relies on liquid chromatography coupled with tandem mass spectrometry. Urine is a common matrix in anti-doping analysis, while blood or plasma may be used in research settings. Sample preparation can involve enzymatic hydrolysis, protein precipitation, or solid-phase extraction before instrumental analysis. Because the compound undergoes metabolism, assays may target the parent molecule, one or more metabolites, or both. Detection windows are not fixed; they depend on factors such as dose, route, individual metabolism, and assay sensitivity. Reference standards are required for accurate identification and quantification.
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.
| Property | Value | Notes |
|---|---|---|
| CAS Registry Number | 317318-70-0 | Unique identifier for the compound. |
| Chemical class | PPARδ agonist | Synthetic ligand for peroxisome proliferator-activated receptor delta. |
| Appearance | White to off-white solid | Typical form of research-grade material. |
| Solubility | Soluble in DMSO and ethanol | Poorly soluble in water. |
| Typical storage | -20°C | Recommended for long-term storage of stock solutions. |
GW501516 acts as a ligand for PPAR delta, a nuclear receptor that regulates transcription of genes involved in fatty acid oxidation and energy use. Activation of this receptor in skeletal muscle shifts metabolism toward fat burning in animal models. The compound does not burn fat directly; it changes gene expression over hours to days. Researchers study it to understand metabolic flexibility and exercise adaptation. Effects observed in rodents are not automatically expected in humans.
Preclinical research reported that GW501516 increased running endurance in mice and improved lipid profiles in some animal species. Early human trials explored effects on high-density lipoprotein cholesterol, triglycerides, and glucose handling, but the program was discontinued. Published human data are sparse and do not establish efficacy for any condition. Studies also examined PPAR delta in cancer biology, with conflicting findings across models. The relationship between receptor activation, tissue context, and disease risk remains an active area of investigation.
GW501516 binds and activates PPARδ, a nuclear receptor that influences transcription of genes involved in fatty acid oxidation and energy use. Activation shifts some metabolic pathways in preclinical models, which is why the compound has been studied for lipid disorders and exercise-related endpoints. The exact downstream effects in humans are incompletely mapped. PPARδ is expressed in many tissues, including skeletal muscle, liver, and adipose tissue, so broad activation may have varied consequences. Researchers continue to examine how selective or partial activation might alter the balance between benefits and risks.
Published human data are sparse and mostly come from early-phase trials. Those studies examined short-term changes in lipids, glucose, and exercise capacity, but they were not large enough to establish efficacy or long-term safety. Some animal experiments reported increased running endurance, yet such findings do not prove a performance benefit in people. Anti-doping laboratories detect GW501516 and its metabolites in urine or blood using liquid chromatography-tandem mass spectrometry. Detection windows depend on dose, sample type, and individual metabolism. The method is sensitive enough to identify trace residues in tested samples.
In September 2010, Iran was attacked by the Stuxnet worm, thought to specifically target its Natanz nuclear enrichment facility. It was a 500-kilobyte computer worm that infected at least 14 industrial sites in Iran, including the Natanz uranium-enrichment plant. Although the official authors of Stuxnet haven't been officially identified, Stuxnet is believed to be developed and deployed by the United States and Israel. The worm is said to be the most advanced piece of malware ever discovered and significantly increases the profile of cyberwarfare. Iranian Cyber Police department, FATA, was dismissed one year after its creation in 2011 because of the arrest and death of Sattar Behesti, a blogger, in the custody of FATA. Since then, the main responsible institution for the cyberwarfare in Iran is the "Cyber Defense Command" operating under the Joint Staff of Iranian Armed Forces. The Iranian state sponsored group MuddyWater is active since at least 2017 and is responsible for many cyber attacks on various sectors.
This can be avoided by breathing air into the mask through the nose. Goggles covering only the eyes are not suitable for deep diving as they cannot be equalised. Dry suit squeeze. The main risk is skin getting pinched and bruised by folds of the dry suit when squeezed on descent. Most dry suits can be equalised against squeeze via a manually operated valve fed from a low pressure gas supply. Air must be manually injected during the descent to avoid squeeze and is manually or automatically vented on the ascent to maintain buoyancy control. Diving helmet squeeze: Helmet squeeze will occur if the gas supply hose is severed above the diver and the non-return valve at the helmet gas inlet fails or is not fitted. Severity will depend on the hydrostatic pressure difference. A very rapid descent, usually by accident, may exceed the rate at which the breathing gas supply can equalise the pressure causing a temporary squeeze. The introduction of the non-return valve and high maximum gas supply flow rates have all but eliminated both these risks. In helmets fitted with a neck dam, the dam will admit water into the helmet if the internal pressure gets too low; this is less of a problem than helmet squeeze but the diver may drown if the gas supply is not reinstated quickly. This form of barotrauma is avoidable by controlled descent rate, which is standard practice for commercial divers, who will use shotlines, diving stages and wet bells to control descent and ascent rates.
== Balanced salt solutions == Alsever's solution Earle's balanced salt solution (EBSS) Gey's balanced salt solution (GBSS) Hanks' balanced salt solution (HBSS) (Dulbecco's) Phosphate buffered saline (PBS) Puck's balanced salt solution Ringer's balanced salt solution (RBSS) Simm's balanced salt solution (SBSS) TRIS-buffered saline (TBS) Tyrode's balanced salt solution (TBSS)
Sources: en.wikipedia.org
== History == Cyclic guanosine monophosphate (cGMP) research began after cGMP and cyclic adenosine monophosphate (cAMP) were identified as cellular components and potentially involved with cellular regulation. Upon the synthesis of cGMP in 1960, progress rapidly spread in the understanding of regulation and effects of cGMP. Earl W. Sutherland received the 1971 Nobel Prize in Medicine for his work with cAMP and secondary messengers. This award sparked extensive research into cAMP, while cGMP received less attention, with its biological functions largely unknown until the 1980s. During this period, two pivotal discoveries highlighted cGMP's role in cellular signaling: atrial natriuretic peptide (ANP) was found to stimulate cGMP synthesis through the particulate guanylyl cyclase (pGC) receptor, and nitric oxide (NO), identified as the endothelium-derived relaxing factor, was shown to activate soluble guanylyl cyclase (sGC), producing cGMP to mediate vasodilation in smooth muscle cells. Further components involved with the cGMP were also identified such as cGMP-hydrolyzing phosphodiesterases (PDEs) and cGMP-binding proteins. The awarding of the 1998 Nobel Prize to Robert F. Furchgott, Louis J. Ignarro, and Ferid Murad for their discoveries in the NO-cGMP pathway renewed interest in cGMP research with the 1st International Conference on cGMP being held in 2003.
When Burger King Corporation began franchising in 1959, it used a regional model where franchisees purchased the right to open stores within a geographic region. These franchise agreements granted BKC very little oversight control of its franchisees and resulted in issues of product quality control, store image and design, and operational procedures. During the 1970s, structural deficiencies in Burger King's franchise system became increasingly problematic for Pillsbury. A major example was the relationship between Burger King and Louisiana-based franchisee Chart House, Burger King's largest franchisee group at the time with over 350 locations in the United States. The company's owners, William and James Trotter, made several moves to take over or acquire Burger King during the 1970s, all of which were spurned by Pillsbury. After the failed attempts to acquire the company, the relationship between Chart House and Burger King soured and eventually devolved into a lawsuit. Chart House eventually spun off its Burger King operations in the early 1980s into a holding company called DiversiFoods which, in turn, was acquired by Pillsbury in 1984 and absorbed into Burger King's operations. As part of the franchising reorganization segment of Operation Phoenix, Donald N. Smith initiated a restructuring of future franchising agreements in 1978.
Malic acid is typically associated with the taste of green apples, while lactic acid is richer and more buttery tasting. Grapes produced in cool regions tend to be high in acidity, much of which comes from the contribution of malic acid. Malolactic fermentation generally enhances the body and flavor persistence of wine, producing wines of greater palate softness. Many winemakers also feel that better integration of fruit and oak character can be achieved if malolactic fermentation occurs during the time the wine is in barrel. A wine undergoing malolactic conversion will be cloudy because of the presence of bacteria, and may have the smell of buttered popcorn, the result of the production of diacetyl. The onset of malolactic fermentation in the bottle is usually considered a wine fault, as the wine will appear to the consumer to still be fermenting (as a result of CO2 being produced). However, for early Vinho Verde production, this slight effervesce was considered a distinguishing trait, though Portuguese wine producers had to market the wine in opaque bottles because of the increase in turbidity and sediment that the "in-bottle MLF" produced. Today, most Vinho Verde producers no longer follow this practice and instead complete malolactic fermentation prior to bottling with the slight sparkle being added by artificial carbonation.
Sources: en.wikipedia.org
Russia and Belarus signed an agreement that formalized the deployment of Russian tactical nuclear weapons in Belarusian territory, with control and usage over the weapons remaining in Russian hands. Shortly afterwards, Belarusian President Aleksandr Lukashenko confirmed that the transfer of weapons to the country had begun and later said countries joining the Union State would also be given nuclear weapons. The Russian Foreign Ministry announced that it was expelling five Swedish diplomats from the country in retaliation for the expulsion of five Russian diplomats from Sweden in April 2023. It also summoned the German, Danish and Swedish ambassadors in protest over a "complete lack of results" in their investigations into the identity of the perpetrators of the 2022 Nord Stream pipeline sabotage. A Swedish appeals court upheld the conviction and life imprisonment of former security services and armed forces employee Peyman Kia for espionage on behalf of Russia. Finland announced it was sending additional military equipment to Ukraine, including anti-aircraft weaponry and ammunition worth 109 million euros ($120 million). Former Russian President Dmitry Medvedev said, during a visit to Vietnam, that he believed that the war with Ukraine could last a "very long time, most likely decades", with periods of truce and then conflict. Medvedev is currently the Deputy Chair of the Security Council of the Russian Federation.
=== Production === Pharmaceutical-grade heparin is derived from mucosal tissues of slaughtered meat animals such as porcine (pig) intestines or bovine (cattle) lungs. Advances to produce heparin synthetically have been made in 2003 and 2008. In 2011, a chemoenzymatic process of synthesizing low molecular weight heparins from simple disaccharides was reported.
== Safety == In vivo dermal sensitization studies according to OECD 429 confirmed HBTU is a moderate skin sensitizer, showing a response at 0.9 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. Thermal hazard analysis by differential scanning calorimetry (DSC) shows HBTU is potentially explosive.
Sources: en.wikipedia.org
Cardarine is a common name for GW501516, a synthetic PPARδ agonist developed for research. It has not been approved as a medication in any country. It is classified as an unapproved drug and a prohibited substance in sport.
No. Cardarine is not an anabolic steroid; it belongs to a different chemical class that targets PPARδ. Steroids act primarily through androgen receptors, while cardarine acts through a nuclear receptor involved in metabolism.
Some rodent studies reported increased endurance and changes in fat metabolism after cardarine exposure. Long-term studies in animals also raised concerns about cancer in certain tissues. Human trial data are limited, so these findings cannot be directly translated to people.
Cardarine targets PPARδ, a nuclear receptor involved in lipid and energy metabolism. It does not bind the androgen receptor in the way SARMs do.