前列腺和精囊的分子生物學(xué),內(nèi)分泌學(xué)和生理學(xué)

1、Development, Molecular Biology, Endocrinology, and Physiology of the Prostate Yu Meng 2015.08.19ContentEndocrinologyProstatic Secretions3Development and Cell Biology12Physiology 4Seminal vesiclesOrigin: mesonephric ductSteroid: testosteroneFeature: extremely resistant to diseaseProstateOrigin: uroge

2、nital sinus epithelium and mesenchymeSteroid: dihydrotestosterone DHTFeature: mesenchymal condensation Stromal-epithelial interactionsProstate cell typesContentEndocrinologyProstatic Secretions3Development and Cell Biology12Physiology 4Androgen Production by the TestesMajor source：Leydig cellsConcen

3、tration：611ng/100mL (10.4-34.7nmol/L) in the plasma 40-50ug/mL in the spermatic vein(75 times)Adrenal androgensDehydroepiandrosterone(DHEA) AndrostenedioneLess than 1% of the total testosterone in the plasma is derived from DHEAAndrostenedione cannot be converted directly to DHT. An important role f

4、or androstenedione in the male may be its peripheral conversion to estrogens through the aromatase reaction. insignificantAndrogen-Binding Proteins in the PlasmaTeBG 57% HSA 40% CBG 1% (1) the affinity of the steroid to bind to a specific protein(2) the capacity, which is the maximal potential bindi

5、ng when all of a binding protein is saturated with bound steroid; the capacity is governed by the amount of binding protein in the plasmaHormone therapyRegulation of Prostate Growth Androgen Action at the Cellular LevelAndrogen ReceptorsLocation: the long arm of the X chromosome at position Xq11.2-q

6、12.AR is a member of the nuclear receptor superfamily which share certain structural features that allow them to regulate gene expression.Mechanism of androgen receptor activation by ligandMechanism of action of the nuclear-activated androgen receptorContentEndocrinologyProstatic Secretions3Developm

7、ent and Cell Biology12Physiology 4Non-peptide componentsNormal human ejaculate: 3 mL(2 - 6 mL) two components: spermatozoa and seminal plasma. Spermatozoa 1% of the total ejaculate, 100 million/mL. Seminal plasma (average 3 mL) :seminal vesicles (1.5 to 2 mL), prostate (0.5 mL), Cowper gland and gla

8、nds of Littre (0.1 to 0.2 mL).Sequential mannerhigh concentrations of potassium, zinc, citric acid,polyamines,fructose, phosphorylcholine, spermine, free amino acids, prostaglandins,and enzymesNon-peptide components The concentration of citrate in the ejaculate is 500 to 1000 times higher than that

9、in the plasma. Prostate secretory epithelial cells form citrate from aspartic acid and glucose. The high concentrations within the prostateresult partly from the inability of the prostate cell mitochondria to oxidize citrate readily once it is formed; therefore, the rate of citrate synthesis far exc

10、eeds the rate of citrate oxidation. Polyamines are the most basic (positively charged) small organic molecules in nature. They occur ubiquitously in tissues at high concentrations and are believed to be involved in diverse physiologic processes that share a relationship to cell proliferation and gro

11、wth. Polyamine and citrate can be quantified in a clinical settingby magnetic resonance spectroscopy.Major Proteins Secreted by the Sex Accessory TissueContentEndocrinologyProstatic Secretions3Development and Cell Biology12Physiology 4Coagulation and Liquefaction of SemenWithin 5 minutes after ejacu

12、lation, human semen coagulates into a semisolid gel. On further standing for a 5- to 20-minute period, the clot spontaneously liquefies to form a viscous liquidDiffer from blood coagulationLiquefaction : plasminogen activators and PSAProstatic Serections and Drug Transporttremendous transport powersOnly a few compounds, including ethanol, iodine, and a few antibiotics, are capable of entering the semen by simple diffusion.A few exceptions for drugs are the basic macrolides erythromycinand oleandomycin, sulfonamides, chloramphenicol,tetracycline, clindamycin, trimethoprim, and f