内脏脂肪 comes up often in conversation and rarely with the context attached. Here we lay out the basics in order, then work through the practical considerations.
Last reviewed on 2025-08-17. Where a claim depends on a specific study, the study is described rather than over-claimed.
Signaling begins at the GHRH receptor, a class B G protein-coupled receptor displayed on somatotroph cells of the anterior pituitary. Receptor occupancy activates Gs proteins, which raise adenylyl cyclase activity and intracellular cyclic AMP, in turn driving protein kinase A dependent pathways. The downstream output is synthesis and pulsatile secretion of growth hormone into the bloodstream. Hepatic tissue and peripheral sites respond by increasing insulin-like growth factor 1 production. Somatostatin and IGF-1 itself supply negative feedback that caps the size and duration of each secretory burst.
Metabolic interest in this compound centers on fat distribution rather than on hormone levels alone. Imaging trials in adults with excess abdominal fat report reductions in visceral adipose tissue, while subcutaneous depots change comparatively little. Growth hormone and IGF-1 are presumed to carry the effect, but the separate contribution of each is not firmly established. Whether these changes persist after treatment stops, and whether they alter longer-term health outcomes, remain open questions that published work does not answer consistently.
Tesamorelin is a synthetic peptide of forty-four amino acids whose sequence reproduces human growth hormone-releasing hormone. Its distinguishing feature sits at the amino terminus, where a trans-3-hexenoyl group replaces the free amine. That acylation slows cleavage by dipeptidyl peptidase IV, an enzyme that otherwise removes the first two residues and inactivates the natural hormone quickly. The modified peptide therefore persists longer in circulation while keeping the same receptor target. It is handled as a lyophilized solid and dissolved shortly before use.
Published work tends to frame tesamorelin as a tool for studying the GHRH axis and as a compound with measurable effects on body composition. Reports often describe visceral adipose tissue as an endpoint, assessed by imaging rather than by inference. Analytical sections commonly describe liquid chromatography with tandem mass spectrometry to confirm identity and purity, because immunoassays may cross-react with related fragments. Where results diverge between studies, differences in assay choice, sampling timing, and population are frequent explanations offered. Whether effects persist after treatment stops remains an open question.
Tesamorelin binds the growth hormone–releasing hormone receptor on pituitary somatotroph cells. The receptor signals through the Gs protein, raising intracellular cAMP and activating protein kinase A. That cascade triggers release of stored growth hormone in pulses rather than a steady stream. Because the drug acts at the receptor that normally controls this process, its effect depends on the body's own signaling architecture rather than on a synthetic pathway. The resulting hormone profile reflects the timing of each pulse, not only its size.
Measured responses usually involve growth hormone and insulin-like growth factor 1, known as IGF-1. Growth hormone rises in bursts and is difficult to sample reliably, while IGF-1 shifts more slowly and can be assessed from a single blood draw. Studies therefore treat IGF-1 as the more practical pharmacodynamic marker. Both are indirect, showing that the receptor was engaged rather than that the peptide reached a particular concentration. Direct exposure measurement requires an assay aimed at the molecule itself.
| Property | Value | Notes |
|---|---|---|
| Molecular class | Synthetic 44-residue peptide | GHRH analog backbone |
| Approximate molecular mass | 5136 Da | Varies with counterion and hydration state |
| N-terminal group | trans-3-hexenoyl | Increases resistance to dipeptidyl peptidase IV |
| Primary receptor | GHRH receptor (GHRHR) | Class B G protein-coupled receptor on somatotrophs |
| Principal mediator | IGF-1 | Rises indirectly after growth hormone release |
作用位置在垂体前叶。tesamorelin 与 GHRH 受体结合后激活腺苷酸环化酶，升高细胞内 cAMP，再经蛋白激酶 A 通路促进生长激素的合成与释放。由于它作用于内源调控节点，生长激素仍以脉冲方式分泌，而不是被持续抬升到固定水平。生长激素随后在肝脏等组织诱导胰岛素样生长因子 1 产生，构成完整的生长激素轴响应。
研究背景集中在特定人群的体成分改变，尤其是与脂肪分布异常相关的内脏脂肪堆积。不同地区对它的监管状态与获批适应症并不一致，部分市场仅限特定诊断人群使用。在一般人群中的长期效应、与其他激素的相互作用以及停药后的维持情况仍属开放问题，现有数据不足以给出普遍结论。
Storage claims vary across suppliers, and published stability data for specific formulations are limited. Extrapolating from related peptides is common but not a substitute for direct measurement. For research use, documentation such as a certificate of analysis is often requested to confirm identity and purity. What constitutes an acceptable purity threshold depends on the intended application. Open questions remain about how temperature excursions during shipping affect long-term peptide integrity. Independent verification by an end user is not routinely reported.
Lyophilized tesamorelin is generally stored refrigerated at 2 to 8 degrees Celsius, protected from light and moisture. Peptides in this class are often kept frozen at minus 20 degrees Celsius for longer periods. Reconstituted solutions are typically used within a defined window because hydrolysis and oxidation proceed faster in liquid form. Container material and headspace also influence how long a preparation retains its expected profile. Specific stability figures depend on concentration and buffer composition.
监管记录显示，特沙莫瑞林于 2010 年在美国首次获得批准，用于人类免疫缺陷病毒感染相关的脂肪营养不良患者。批准依据来自降低内脏脂肪的临床试验，而非体重或瘦体重的普遍改善。后续出现了不同制剂版本，但其核心适应症保持一致。关于长期心血管结局和死亡率影响，现有证据仍不充分。
在临床研究之外，特沙莫瑞林常被讨论为生长激素分泌促进剂，但这一说法需要限定。它并不等同于生长激素本身，也不属于普通减重药物。部分研究关注其减少腹部脂肪和改善脂质谱的潜力，另一些研究则关注胰岛素抵抗和 IGF-1 升高等信号。这些效应的临床意义仍在评估中，尚未形成统一结论。
==== Israel ==== In the 2006 war against Hezbollah, Israel alleges that cyber-warfare was part of the conflict, where the Israel Defense Forces (IDF) intelligence estimates several countries in the Middle East used Russian hackers and scientists to operate on their behalf. As a result, Israel attached growing importance to cyber-tactics, and became, along with the U.S., France and a couple of other nations, involved in cyber-war planning. Many international high-tech companies are now locating research and development operations in Israel, where local hires are often veterans of the IDF's elite computer units. Richard A. Clarke adds that "our Israeli friends have learned a thing or two from the programs we have been working on for more than two decades." In September 2007, Israel carried out an airstrike on a suspected nuclear reactor in Syria dubbed Operation Orchard. U.S. industry and military sources speculated that the Israelis may have used cyberwarfare to allow their planes to pass undetected by radar into Syria. Following US President Donald Trump's decision to pull out of the Iran nuclear deal in May 2018, cyber warfare units in the United States and Israel monitoring internet traffic out of Iran noted a surge in retaliatory cyber attacks from Iran. Security firms warned that Iranian hackers were sending emails containing malware to diplomats who work in the foreign affairs offices of US allies and employees at telecommunications companies, trying to infiltrate their computer systems.
=== De–Di === Christian de Duve FRS (foreign associate) (1917–2013). Belgian cytologist and biochemist at the Université Catholique de Louvain, known for discovering peroxisomes and lysosomes. Nobel Prize for Physiology or Medicine (1974). Foreign Associate Natl. Acad. Sci. USA. Michael W. Deem (PhD 1994). American biochemist and genetic engineer at Rice University, known for work in evolution, immunology, and materials. William DeGrado (b. 1955). American pharmaceutical chemist at UC San Francisco, known for protein design, synthesis of peptidomimetics, and characterizing membrane-active peptides and proteins. Member Natl. Acad. Sci. USA. Max Delbrück FRS (1906–1981). German-American biophysicist at Caltech. Nobel Prize in Physiology or Medicine (1969). Member Natl. Acad. Sci. USA. Hector DeLuca (b. 1930). American biochemist at the University of Wisconsin, known for work on vitamin D. Member Natl. Acad. Sci. USA. Pierre De Meyts (1944–2025). Belgian physician and biochemist at the Université Catholique de Louvain, known for studies of hormone-receptor interaction of peptide hormones and the physiopathogenesis of diabetes. Willey Glover Denis (1879–1929). American biochemist at Tulane University, a pioneer in clinical chemistry and the measurement of protein in biological fluids. Rosa Devés (born 1950), Chilean biochemist, first woman rector of the University of Chile. Richard E. Dickerson (1931–2025), American biochemist, the first to carry out a single-crystal structure analysis of B-DNA. Zacharias Dische (1895–1988).
A system of measure for timber in the round (standing or felled), now largely superseded by the metric system except in measuring hardwoods in certain countries. Its purpose is to estimate the value of sawn timber in a log, by measuring the unsawn log and allowing for wastage in the mill. Following the so-called "quarter-girth formula" (the square of one quarter of the circumference in inches multiplied by 1⁄144 of the length in feet), the notional log is four feet in circumference, one inch of which yields the hoppus board foot, 1 foot yields the hoppus foot, and 50 feet yields a hoppus ton. This translates to a hoppus foot being equal to 1.273 cubic feet (2,200 in3; 0.0360 m3). The hoppus board foot, when milled, yields about one board foot. The volume yielded by the quarter-girth formula is 78.54% of cubic measure (i.e. 1 ft3 = 0.7854 h ft; 1 h ft = 1.273 ft3).
=== Drinking water and products === In April 2024 EPA issued a final drinking water rule for PFOA, PFOS, GenX, PFBS, PFNA, and PFHxS. Public water systems must remove these six PFAS to near-zero levels by 2027. Grant funding is available from EPA to assist utilities in water testing and development of treatment systems. The State of New Jersey published drinking water standards for PFOA and PFOS in 2020. A standard for PFNA was published in 2018. This was the first state to publish PFAS standards in the absence of federal regulations. See U.S. state government actions. In 2018 the State of New York adopted drinking water standards of 10 ppt for PFOA and 10 ppt for PFOS, the most stringent such standards in the United States. The standards apply to public water systems and took effect in 2019 after a public comment period. Using information gained through a Freedom of Information Act request, in May 2018 it was learned that January 2018 emails between the EPA, the Office of Management and Budget, the Department of Defense, and the Department of Health and Human Services showed an effort to suppress the release of a draft report on the toxicology of PFOS and PFOA done by the Agency for Toxic Substances and Disease Registry. The report found that these chemicals endanger human health at a far lower level than EPA has previously called safe. After media accounts of the effort surfaced, the regional EPA administrator for Colorado denied that EPA had anything to do with suppressing the report. The report was released on June 21, 2018.
A feline litter usually consists of two to five kittens, but litters with one to more than ten are known. Kittens are typically born after a gestation lasting between 64 and 67 days, with an average length of 66 days. When they are born, kittens emerge in a sac called the amnion, which is bitten off and eaten by the mother cat. For the first several weeks, kittens cannot urinate or defecate without being stimulated by their mother. They also cannot regulate their body temperature for the first three weeks, so kittens born in temperatures less than 27 °C (81 °F) can die from hypothermia if their mother does not keep them warm. The mother's milk is very important for the kittens' nutrition and proper growth. This milk transfers antibodies to the kittens, which helps protect them against infectious diseases. As mentioned above, they cannot urinate, so they have a very high requirement for fluids. Kittens open their eyes about seven to ten days after birth. At first, the retina is poorly developed and vision is poor. Kittens cannot see as well as adult cats until about ten weeks after birth. Kittens develop very quickly from about two weeks of age until their seventh week. Their coordination and strength improve, and they play-fight with their littermates and begin to explore the world outside the nest or den. They learn to wash themselves and others as well as play hunting and stalking games, showing their inborn ability as predators; the kittens' mother or other adult cats help develop these innate skills by bringing live prey to the nest.
Sources: en.wikipedia.org
As this is a cube, the top and bottom surfaces are identical in shape and area, and the pressure difference between the top and bottom of the cube is directly proportional to the depth difference, and the resultant force difference is exactly equal to the weight of the fluid that would occupy the volume of the cube in its absence. This means that the resultant upward force on the cube is equal to the weight of the fluid that would fit into the volume of the cube, and the downward force on the cube is its weight, in the absence of external forces. This analogy is valid for variations in the size of the cube. If two cubes are placed alongside each other with a face of each in contact, the pressures and resultant forces on the sides or parts thereof in contact are balanced and may be disregarded, as the contact surfaces are equal in shape, size and pressure distribution, therefore the buoyancy of two cubes in contact is the sum of the buoyancies of each cube. This analogy can be extended to an arbitrary number of cubes. An object of any shape can be approximated as a group of cubes in contact with each other, and as the size of the cubes is decreased, the precision of the approximation increases. The limiting case for infinitely small cubes is the exact equivalence. Angled surfaces do not nullify the analogy as the resultant force can be split into orthogonal components and each dealt with in the same way.
===== Other delivery methods: substance delivery in medical use ===== Near-infrared light: Drug release is triggered from heat. The infrared technology can be absorbed deep in the body, turn to heat. The heat-sensitive material, particularly a polymer shell that swells upon heating, collapses. The action of deflating is what releases the drug. Magnetic fields: Magnetic bars of millimeter-scale are embedded in poly(vinyl alcohol). The magnetic field within the bars is alternated, which results in the change of shape and ultimate collapse of the nanocapsules. The change in the structure then triggers the drug release. Ultrasound: Another option of drug release is through ultrasound, which is a "longitudinal pressure wave". The ultrasound can either be low-frequency, or LFUS, (between ~20 and ~100 kHz) or high-frequency, HFUS, (>1 MHz). Transdermal delivery (sonophoresis) is enhanced through LFUS, which then further allows the drug to be released. Since the wave of HFUS is higher, success of drug delivery has been demonstrated through the form of bubbles. The bubbles with in the capsule are formed and collapsed due to the higher temperatures of the wave. Some other ways include oral, which is the most active, nasal, transdermal, and through the lung. Oral is the most common, and the most challenging. Demands for consistent release persist, although developments are being made for drugs to bioadhere to the intestinal tract. Bioadhesion is also being considered for nasal delivery, to prolong the life of the drug within the nose.
=== Metabolic === In acute hyperglycemia, ketoacidosis may develop because decreased insulin levels increase the activity of hormone sensitive lipase. The degradation of triacylglycerides by hormone-sensitive lipase produces free fatty acids that are eventually converted to acetyl-coA by beta-oxidation. Ketoacidosis is a life-threatening condition which requires immediate treatment. Symptoms include: shortness of breath, breath that smells fruity (such as pear drops), nausea and vomiting, and very dry mouth. Another life-threatening consequence of hyperglycemia is nonketotic hyperosmolar syndrome.
Periodic actin rings – A periodic structure constructed of evenly spaced actin rings is found in axons. In this structure, the actin rings, together with spectrin tetramers that link the neighboring actin rings, form a cohesive cytoskeleton that supports the axon membrane. The structure periodicity may also regulate the sodium ion channels in axons.
Sources: en.wikipedia.org
One theory says the submarine sandwich was brought to the U.S. by Dominic Conti (1874–1954), an Italian immigrant who came to New York in the late-19th century. He supposedly named it "submarine roll" after seeing the recovered 1901 submarine called Fenian Ram in the Paterson Museum of New Jersey in 1928. His granddaughter said:
Two or more of these techniques are often combined. This can improve preservation and reduce unwanted side effects such as the denaturation of nutrients by severe heat treatments. Common combinations are salting/drying, salting/marinating, salting/smoking, drying/smoking, pasteurization/refrigeration and controlled atmosphere/refrigeration. Other process combinations are currently being developed along the multiple hurdle theory.
=== Pharmacology === Preclinical and early clinical pharmacology studies characterized insulin icodec as a basal insulin analogue. The molecular modifications were intended to create an albumin-bound circulating depot, while preserving insulin receptor-mediated metabolic activity and limiting mitogenic activity relative to human insulin.
Norepinephrine (NE), also called noradrenaline (NA) or noradrenalin, is an organic chemical in the catecholamine family that functions in the brain and body as a hormone, neurotransmitter and neuromodulator. The name "norepinephrine" (from Ancient Greek ἐπῐ́ (epí), "upon", and νεφρός (nephrós), "kidney") is usually preferred in the United States, whereas "noradrenaline" (from Latin ad, "near", and ren, "kidney") is more commonly used in the United Kingdom and the rest of the world. "Norepinephrine" is also the international nonproprietary name given to the drug. Regardless of which name is used for the substance itself, parts of the body that produce or are affected by it are referred to as noradrenergic. The general function of norepinephrine is to mobilize the brain and body for action. Norepinephrine release is lowest during sleep, rises during wakefulness, and reaches much higher levels during situations of stress or danger, in the so-called fight-or-flight response. In the brain, norepinephrine increases arousal and alertness, promotes vigilance, enhances formation and retrieval of memory, and focuses attention; it also increases restlessness and anxiety. In the rest of the body, norepinephrine increases heart rate and blood pressure, triggers the release of glucose from energy stores, increases blood flow to skeletal muscle, reduces blood flow to the gastrointestinal system, and inhibits voiding of the bladder and gastrointestinal motility. In the brain, noradrenaline is produced in nuclei that are small yet exert powerful effects on other brain areas.
=== Patent litigation === The PEGylated lipid nanoparticle drug delivery (LNP) system of the mRNA vaccine known as mRNA-1273 has been the subject of ongoing patent litigation with Arbutus Biopharma, from whom Moderna had previously licensed LNP technology. On 4 September 2020, Nature Biotechnology reported that Moderna had lost a key challenge in the ongoing case.
Sources: en.wikipedia.org
The amino acid sequence matches human growth hormone-releasing hormone, but the amino terminus carries a trans-3-hexenoyl group instead of a free amine. That single structural change chiefly affects enzymatic stability rather than receptor selectivity.
Growth hormone released from the pituitary stimulates IGF-1 production in the liver and other tissues, so circulating IGF-1 generally rises during exposure. The size of the rise varies between individuals and depends on baseline hormonal status and other concurrent factors.
Reported imaging studies focus on visceral adipose tissue, where reductions are more consistently observed across trials. Subcutaneous depots show smaller and less reproducible changes, so the two compartments should not be treated as equivalent.
It acts on the growth hormone–releasing hormone receptor, a Gs-coupled receptor found on pituitary somatotroph cells. Activation raises cAMP and prompts pulsatile hormone release.