If you have been reading about circadian rhythm 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 2025-09-28. Where a claim depends on a specific study, the study is described rather than over-claimed.
Preclinical reports have linked SR9009 to improved endurance and altered energy expenditure in rodents. Such findings have prompted interest in whether REV-ERB activation can influence skeletal muscle metabolism. However, the reported effects depend on dose, route, and experimental model, and replication across laboratories is limited. Human trials have not established comparable outcomes, so claims about exercise performance remain speculative. The absence of controlled human data is a central limitation in interpreting these observations.
The mechanism of action involves binding to REV-ERB receptors and recruiting corepressor complexes, which represses target gene transcription. This contrasts with many nuclear receptor agonists that activate transcription. Downstream effects may include changes in autophagy, mitochondrial biogenesis, and lipid handling, but the precise pathways remain an active area of study. Whether these molecular events translate into meaningful physiological effects in humans is unresolved. Most evidence comes from cultured cells and rodent models rather than human participants.
SR9009 is a synthetic small molecule studied as an agonist of the nuclear receptors REV-ERBα and REV-ERBβ. These receptors help regulate circadian rhythms and metabolic gene expression. In laboratory experiments, SR9009 binds these receptors and alters transcription of genes involved in lipid handling, glucose metabolism, and mitochondrial function. It is not a naturally occurring compound and has no approved therapeutic use. Research interest stems from its ability to modify energy metabolism in cells and animal models.
In rodent studies, SR9009 has been reported to increase mitochondrial content in skeletal muscle and improve exercise endurance under some conditions. These findings led to popular descriptions such as an exercise mimetic, although that term oversimplifies the biology. Effects vary by dose, timing, tissue, and model. The compound's influence on circadian pathways means that time of administration can matter in experiments. Whether similar metabolic changes occur in humans remains largely unexplored in controlled published trials.
Pharmacokinetic data for SR9009 are limited in published literature. Some reports indicate low oral bioavailability and rapid clearance in animals, which complicates interpretation of exposure and effect. Researchers often use injected routes in preclinical work to achieve measurable systemic levels. Analytical studies rely on mass spectrometry to detect the parent compound and its metabolites. Questions about tissue distribution, active metabolites, and long-term consequences remain open. Species differences in metabolism can affect observed half-life and target engagement.
| Property | Value | Notes |
|---|---|---|
| Chemical class | Synthetic REV-ERB agonist | Small molecule; not a steroid or peptide. |
| Primary targets | NR1D1 and NR1D2 | Also known as REV-ERBα and REV-ERBβ. |
| Studied routes | Intraperitoneal in rodents | Oral bioavailability in humans is not established. |
| Human approval | No approved therapeutic indication | No recognized clinical use. |
| Key uncertainty | Human physiological effects | Preclinical findings may not translate. |
SR9009 is a synthetic small molecule studied as an agonist of REV-ERB nuclear receptors. REV-ERB alpha and REV-ERB beta help regulate circadian rhythms and metabolic gene expression. In laboratory research, SR9009 has been used to probe how these receptors affect skeletal muscle, liver, and adipose tissue. The compound was identified in academic drug-discovery work and is often described in scientific literature by its chemical name and research code. It is not an approved medicine, and human clinical data remain limited or absent.
SR9009 binds REV-ERB receptors and alters their repressive activity on target genes. This action can change transcription of genes involved in lipid handling, glucose metabolism, and mitochondrial function. In rodent studies, treated animals have shown changes in muscle oxidative capacity and exercise performance, though effects vary by dose, duration, and model. The precise molecular steps connecting receptor binding to whole-body outcomes are still an active area of investigation. Findings in animals do not automatically translate to humans.
Because REV-ERB receptors are core clock components, SR9009 has been examined for effects on daily rhythms as well as metabolism. Research has explored whether the compound can shift or reinforce circadian gene expression in tissues such as liver and muscle. Some studies report improved metabolic markers in obese or diabetic mice, while others show context-dependent responses. Questions remain about which effects are direct, which are secondary to timing, and how they might differ across species.
Regulatory treatment of SR9009 reflects its investigational status. The compound has no approved human therapeutic indication, and sports authorities prohibit its use. It appears on anti-doping lists as a non-approved substance or metabolic modulator, depending on the list version. Products sold online as research chemicals are not quality-controlled medicines, so their identity and purity can differ from the label. Such products may also contain unlisted compounds, which complicates both testing and safety assessment.
Scientific discussion of SR9009 often separates animal evidence from human anecdote. Rodent studies provide controlled data on endurance, metabolism, and gene expression, but they use specific strains, doses, and treatment durations. Human reports are mostly uncontrolled and cannot establish cause and effect. Open questions include oral bioavailability, tissue distribution, metabolic stability, and long-term effects. Review articles generally call for more rigorous pharmacokinetic and safety research before any clinical use could be considered.
The new refrigerating technology first met with widespread industrial use as a means to freeze meat supplies for transport by sea in reefer ships from the British Dominions and other countries to the British Isles. Although not actually the first to achieve successful transportation of frozen goods overseas (the Strathleven had arrived at the London docks on 2 February 1880 with a cargo of frozen beef, mutton and butter from Sydney and Melbourne), the breakthrough is often attributed to William Soltau Davidson, an entrepreneur who had emigrated to New Zealand. Davidson thought that Britain's rising population and meat demand could mitigate the slump in world wool markets that was heavily affecting New Zealand. After extensive research, he commissioned the Dunedin to be refitted with a compression refrigeration unit for meat shipment in 1881. On February 15, 1882, the Dunedin sailed for London with what was to be the first commercially successful refrigerated shipping voyage, and the foundation of the refrigerated meat industry. The Times commented "Today we have to record such a triumph over physical difficulties, as would have been incredible, even unimaginable, a very few days ago ...". The Marlborough — sister ship to the Dunedin — was immediately converted and joined the trade the following year, along with the rival New Zealand Shipping Company vessel Mataurua, while the German Steamer Marsala began carrying frozen New Zealand lamb in December 1882.
=== Books === Separation Processes (1971); 2nd edition (1980) Freeze Drying of Foods (1971) The University of California: Creating, Nurturing, and Maintaining Academic Quality in a Public University Setting (2018)
Scanners are used to monitor emergency police, fire, and ambulance frequencies, as well as other two way radio frequencies such as citizens band. Scanning capabilities have also become a standard feature in communications receivers, walkie-talkies, and other two-way radios. Communications receiver or shortwave receiver - a general purpose audio receiver covering the LF, MF, shortwave (HF), and VHF bands. Used mostly with a separate shortwave transmitter for two-way voice communication in communication stations, amateur radio stations, and for shortwave listening.
Sources: en.wikipedia.org
Liakhov, a vigorous, able, and reactionary officer firmly committed to upholding absolute monarchies whatever in Russia or Iran, transformed the Persian Cossack Brigade into a mounted para-military police force rather than as a combat force. Liakhov was close to the new Shah, Mohammed Ali, who ascended to the Peacock Throne in January 1907, and it was due to the shah's patronage that Liakhov transformed the Persian Cossack Brigade into the main bulwark of the Iranian state. In June 1908, Liakhov led the Cossack Brigade in bombarding the Majlis (Parliament) while being appointed military governor of Tehran as the shah attempted to do away with the constitution his father had been forced to grant in 1906 Reza Khan, who became the first Iranian to command the Cossack Brigade led the coup d'état in 1921 and in 1925 deposed the Qajars to found a new dynasty. After the outbreak of World War I in August 1914, Cossacks became a key component in the cavalry of the Imperial Russian Army. The mounted Cossacks made up 38 regiments, plus some infantry battalions and 52 horse artillery batteries. Initially, each Russian cavalry division included a regiment of Cossacks in addition to regular units of hussars, lancers, and dragoons. By 1916, the Cossacks' wartime strength had expanded to 160 regiments, plus 176 independent sotnias (squadrons) employed as detached units. The importance of cavalry in the frontlines faded after the opening phase of the war settled into a stalemate.
== Related enzymes == Other enzymes involved in the catabolism of phenylalanine include phenylalanine hydroxylase, aminotransferase, p-hydroxyphenylpyruvate dioxygenase, homogentisate oxidase, and fumarylacetoacetate hydrolase. Mutations in some of these enzymes can lead to more severe diseases such as, phenylketonuria, alkaptonuria, and tyrosinemia. The gene GSTZ1 is located on chromosome 14q24.3.
For example, chronic alcohol consumption will induce Cytochrome P450 enzymes, like CYP2E1, which enhances the metabolism of ethanol. As a consequence, the induction of CYP2E1 will increase a person's tolerance levels and reduce the toxicity of ethanol. Additionally, CYP2E1 is involved with the metabolism of acetaldehyde (CH₃CHO), a metabolite of alcohol that is highly reactive and toxic, which can contribute to an alcohol-induced liver injury along with overoxidation. Various physiological and pathological factors can also affect drug metabolism. Physiological factors that can influence drug metabolism include age, individual variation (e.g., pharmacogenetics), enterohepatic circulation, nutrition, sex differences or gut microbiota. This last factor has significance because gut microorganisms are able to chemically modify the structure of drugs through degradation and biotransformation processes, thus altering the activity and toxicity of drugs. These processes can decrease the efficacy of drugs, as is the case of digoxin in the presence of Eggerthella lenta (E. lenta) in the microbiota. Genetic variation (polymorphism) accounts for some of the variability in the effect of drugs. An example of polymorphism affecting drug metabolism is the alcohol flush reaction caused by the ALDH2 genetic mutation. The ALDH2 genetic mutation is prevalent among east Asians and causes a reduced activity of aldehyde dehydrogenase (ALDH), which assists in breaking down acetaldehyde (CH₃CHO).
Sources: en.wikipedia.org
A dog is of a very hot nature: he should therefore never be without clean water by him, that he may drink when he is thirsty. In regard to their food, carrion is by no means proper for them. It must hurt their sense of smelling, on which the excellence of these dogs greatly depends. Barley meal, the dross of wheatflour, or both mixed together, with broth or skim'd milk, is very proper food. For change, a small quantity of greaves from which the tallow is pressed by the chandlers, mixed with their flour; or sheep's feet well baked or boiled, are a very good diet, and when you indulge them with flesh it should always be boiled. In the season of hunting your dogs, it is proper to feed them in the evening before, and give them nothing in the morning you take them out, except a little milk. If you stop for your own refreshment in the day, you should also refresh your dogs with a little milk and bread. In 1833, The Complete Farrier gave similar but far more extensive advice on feeding dogs:
== June 10, 1915 (Thursday) == Francisco Lagos Cházaro became acting president of Mexico under convention of the Convention of Aguascalientes. Battle of Hébuterne — The French secured more trenches from the Germans on the southern flank. Second Battle of Garua — The remaining 249 German and native troops stationed in garrisons around Garua, Kamerun surrendered to British and French forces. British seaplane carrier HMS Ben-my-Chree arrived at Lesbos to provide a full squadron of fighter planes and bombers for the Allied landing forces at Gallipoli. Royal Navy torpedo boats HMS TB 10 and HMS TB 12 both struck mines in the North Sea, with a total 45 men lost. Filmmakers Edwin S. Porter and William E. Waddell tested the first 3D film to an audience at the Astor Theatre in New York City. The only Vorticist exhibition ever staged opened at the Doré Gallery in London. The popular Italian sports magazine Hurrà Juventus was first published for players and fans of the Juventus association football club in Turin. Born: Saul Bellow, Canadian-American writer, recipient of the Nobel Prize in Literature; as Solomon Bellows, in Lachine, Quebec, Canada (d. 2005) Inia Te Wiata, New Zealand Māori opera singer, known for his performances in The Marriage of Figaro, La bohème, Billy Budd and Gloriana; as Inia Morehu Tauhia Watene Iarahi Waihurihia Te Wiata, in Ōtaki, New Zealand (d. 1971) Died: William Hayman Cummings, 83, English organist and singer, founder of the Purcell Society and credited for creating the melody known today for the Christmas carol "Hark! The Herald Angels Sing" (b. 1831)
tracer A molecule or a specific atom within a molecule that has been chemically or radioactively labelled so that it can be easily tracked or followed through a biochemical process or located in a cell or tissue.
=== Zinc selenide white LEDs === Experimental white LEDs have been developed using homoepitaxially grown zinc selenide (ZnSe) on ZnSe substrates. These LEDs lack the yellow phosphors found in conventional white LEDs. In ZnSe LEDs, the active region emits blue light, while the conductive ZnSe substrate emits yellow light, resulting in white light output. Researchers suggest these LEDs offer lower operating voltages and a wider range of color temperatures than conventional white LEDs.
Sources: en.wikipedia.org
It is a synthetic compound that acts as an agonist at REV-ERBα and REV-ERBβ. It is used mainly as a research chemical to study circadian and metabolic pathways. It is not approved for human therapeutic use.
REV-ERB receptors generally repress transcription when bound by natural heme. SR9009 is described as an agonist that enhances this repressive activity. The result is altered expression of clock and metabolic genes.
Published controlled human trials are lacking. Some sources cite limited or unofficial reports, but these do not establish safety or efficacy. Claims about human performance effects remain unverified.
It is a synthetic research compound that activates REV-ERB nuclear receptors. It is not an approved drug or dietary supplement. Most information comes from cell and animal studies.