Tag: Steroids
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Steroidogenic factor 1Â (SF-1)Â protein and a few related things
The steroidogenic factor 1 (SF-1) protein is a transcription factor involved in sex determination by controlling the activity of genes related to the reproductive glands or gonads and adrenal glands. This protein is encoded by the NR5A1 gene, a member of the nuclear receptor subfamily, located on the long arm of chromosome 9 at position 33.3. It was originally identified as a regulator of genes encoding cytochrome P450 steroid hydroxylases, however, further roles…
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Sterol carrier proteins (aka nonspecific lipid transfer proteins)
These proteins are different from plant nonspecific lipid transfer proteins but structurally similar to small proteins of unknown function from Thermus thermophilus. This domain is involved in binding sterols. The human sterol carrier protein 2 (SCP2) is a basic protein that is believed to participate in the intracellular transport of cholesterol and various other lipids. Human…
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Farnesol and Farnesene
Farnesol is a natural 15-carbon organic compound which is an acyclic sesquiterpene alcohol. Under standard conditions, it is a colorless liquid. It is hydrophobic, and thus insoluble in water, but miscible with oils. Farnesol is produced from 5-carbon isoprene compounds in both plants and animals. Phosphate-activated derivatives of farnesol are the building blocks of possibly all acyclic sesquiterpenoids. These compounds are doubled to…
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Phytoecdysteroids are plant-derived ecdysteroids
Phytoecdysteroids are plant-derived ecdysteroids. Phytoecdysteroids are a class of chemicals that plants synthesize for defense against phytophagous (plant eating) insects. These compounds are mimics of hormones used by arthropods in the molting process known as ecdysis. When insects eat the plants with these chemicals they may prematurely molt, lose weight, or suffer other metabolic damage and die. Chemically,…
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The halloween genes
The halloween genes are a set of genes identified in Drosophila melanogaster that influence embryonic development. All of the genes code for cytochrome P450 enzymes in the ecdysteroidogenic pathway (biosynthesis of ecdysone from cholesterol). Ecdysteroids such as 20-hydroxyecdysone and ecdysone influence many of the morphological, physiological, biochemical changes that occur during molting in insects. Steroid hormones control many aspects of reproduction, development, and homeostasis in higher organisms. In arthropods, steroid hormones play equal or even more…
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Chrysolina beetles, including Chrysolina coerulans, have cardiac glycosides (including xylose) in their defensive glands
The defensive secretions of some chrysomelid beetles belonging to the genera Chrysolina, Chrysochloa, and Dlochrysa contain complex mixtures of cardenolides. The spectral data for some of these compounds suggest that they are monohydroxylated digitoxigenin derivatives linked to a pentose (such as xylose or arabinose). Evidence indicates that the beetles do not sequester these steroid glycosides…
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Leydig cells aka interstitial cells of the testes and interstitial cells of Leydig
Leydig cells, also known as interstitial cells of the testes and interstitial cells of Leydig, are found adjacent to the seminiferous tubules in the testicle and produce testosterone in the presence of luteinizing hormone (LH).[1][2] They are polyhedral in shape and have a large, prominent nucleus, an eosinophiliccytoplasm, and numerous lipid-filled vesicles.[3] Structure The mammalian Leydig cell is a polyhedral epithelioid cell with a single eccentrically located ovoid nucleus.…
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The drug phencyclidine (PCP or ‘Angel Dust’) antagonizes glutamic acid non-competitively at the NMDA receptor
The drug phencyclidine (more commonly known as PCP or ‘Angel Dust’) antagonizes glutamic acid non-competitively at the NMDA receptor. For the same reasons, dextromethorphan and ketamine also have strong dissociative and hallucinogenic effects. Acute infusion of the drug LY354740 (also known as eglumegad, an agonist of the metabotropic glutamate receptors2 and 3) resulted in a marked diminution of yohimbine-induced stress response in bonnet macaques (Macaca radiata); chronic oral administration of LY354740 in those animals led to markedly reduced baseline cortisol levels…
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20α,22R-Dihydroxycholesterol
20α,22R-Dihydroxycholesterol, or (3β)-cholest-5-ene-3,20,22-triol is an endogenous, metabolic intermediate in the biosynthesis of the steroid hormones from cholesterol. Cholesterol ((3β)-cholest-5-en-3-ol) is hydroxylated by cholesterol side-chain cleavage enzyme (P450scc) to form 22R-hydroxycholesterol, which is subsequently hydroxylated again by P450scc to form 20α,22R-dihydroxycholesterol, and finally the bond between carbons 20 and 22 is cleaved by P450scc to form pregnenolone ((3β)-3-hydroxypregn-5-en-20-one), the precursor to the steroid hormones. CHAUDHURI AC, HARADA Y, SHIMIZU K, GUT M, DORFMAN RI (March 1962). “Biosynthesis of pregnenolone from…
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22R-Hydroxycholesterol
22R-Hydroxycholesterol, or (3β)-cholest-5-ene-3,22-diol is an endogenous, metabolic intermediate in the biosynthesis of the steroid hormones from cholesterol. Cholesterol ((3β)-cholest-5-en-3-ol) is hydroxylated by cholesterol side-chain cleavage enzyme (P450scc) to form 22R-hydroxycholesterol, which is subsequently hydroxylated again by P450scc to form 20α,22R-dihydroxycholesterol, and finally the bond between carbons 20 and 22 is cleaved by P450scc to form pregnenolone ((3β)-3-hydroxypregn-5-en-20-one), the precursor to the steroid hormones. [CHAUDHURI AC, HARADA Y, SHIMIZU K, GUT M, DORFMAN RI (March 1962). “Biosynthesis of pregnenolone…
