Smooth endoplasmic reticulum (SER) NoneribosomeAttachedEndoplasmic reticulumIt is called smooth endoplasmic reticulum, usually smallMembranous tubeAnd small membranous sacs, rather than flat membranous sacs, are widely found in various types of cells, including those that synthesize cholesterolEndocrine glandCells, muscle cellsRenal cellEtc.The smooth endoplasmic reticulum islipidIt is an important place for synthesis. It is often used as the site for budding, and the endoplasmic reticulumproteinOr lipids are transported to Golgi apparatus.The smooth endoplasmic reticulum has many important functions, such as steroid hormone synthesis, liver cell detoxification,Glycogen decompositionreleaseglucose，Muscle contractionAdjustment, etc.The smooth endoplasmic reticulum is an important site for lipid synthesis, which is often used as the site of budding to transport proteins or lipids synthesized on the endoplasmic reticulum toGolgi apparatus。The rough endoplasmic reticulum corresponds to the smooth endoplasmic reticulum.Rough endoplasmic reticulumMost of them are large flat membrane sacs, which are arranged very neatly under the electron microscope. They are composed of ribosome and endoplasmic reticulumComposite machineEnergy structure, ubiquitous inSecretory proteinIts main function is to synthesize secreted proteinsMembrane proteinandEnzyme protein。[1]
The smooth endoplasmic reticulum is mostly vesicular, which is only abundant in some cells, and has different functions due to different acids.
①Steroid hormoneThe synthesis of, in the cell that secretes steroid hormone;The smooth endoplasmic reticulum membrane hasEnzyme system, the cholesterol synthesized here is converted into steroid hormone;
② Lipid Metabolism, Small IntestineAbsorptive cellIntake of fatty acidsglycerolandMonoglyceride, esterified on smooth endoplasmic reticulum totriglyceride，HepatocyteThe fatty acid ingested is also found on the smooth endoplasmic reticulumOxidoreductaseDecomposition, or re esterification;The smooth endoplasmic reticulum can also participate in the desaturation of fatty acids.
③ The smooth endoplasmic reticulum of liver cells contains various enzymes involved in detoxification, some foreign drugs, toxicMetabolitesAnd hormones are treated here by oxidation, reduction, hydrolysis or combination, and become non-toxic substances to be discharged from the body;
Under physiological conditions, the number of smooth endoplasmic reticulum (SER) changes with the rise and fall of cell function.However, the opposite may also occur, for example, in some diseases (such asCholestasis ）When, frommorphological structure Seen from the above, the smooth endoplasmic reticulum of hepatocytes is significantly proliferated, but itsMixed functional oxidaseOn the contrary, its activity decreases, which is actually a manifestation of cell failure.
The smooth endoplasmic reticulum of hepatocytes has the function of biotransformation, which can transform and detoxify some low molecular substances such as drugs, drugs, poisons, etcIndirect bilirubinConvert toDirect bilirubin。
manyAddictionDrugs andaddictive thingsasBarbiturates, drug abuse, alcoholism, etc., can lead to the proliferation of smooth endoplasmic reticulum of liver cells, and long-term useOral contraceptives、sleeping pill, antidiabetesDrugs can also lead to the same consequences.stayHBsAgpositivehepatitisThe smooth endoplasmic reticulum in hepatocytes proliferates significantly, forming HBsAg in its ducts. Due to the large proliferation of smooth endoplasmic reticulum, this hepatocyteoptical microscopeDownward presentationGround glassAppearance, so it is called ground glass cell, and can beLichen red(orcein) Staining.
stayCell damageTime sideEndoplasmic reticulumIt may also occur that the tubules break down intoVesicleOr expanded into big bubbles.In medicine and someAromatic compound(MainlyCarcinogen）Under the influence ofCytoplasmIt forms scallion skin insideLayered structure, that is, "accessory nucleus", which can be collected and sorted by medical education and education networkAdaptive response(loose structure) or denaturalization (dense structure).
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Smooth endoplasmic reticulum hyperplasia
Smooth endoplasmic reticulum hyperplasiaSterolSubstance, detoxificationhormoneDeactivation and other functions, such asDetoxificationenhance,HepatocyteIncreased endoplasmic reticulum on the inner smooth surface, and the inner smooth surface of adrenal cortical tumorEndoplasmic reticulumAlso many.
Sarcoplasmic reticulum edema Sarcoplasmic reticulum also belongs to smooth endoplasmic reticulum, andMuscle contractionandcalcium ionRelease recovery related.muscle cellsIn case of hypoxia and poisoning, sarcoplasmic reticulum may have edema.
