Brosens J J, Barker F G, de Souza N M
Institute of Obstetrics and Gynaecology, Imperial College School of Medicine at Hammersmith Hospital, London, UK.
Hum Reprod Update. 1998 Sep-Oct;4(5):496-502. doi: 10.1093/humupd/4.5.496.
Human non-gravid myometrium differentiates in response to ovarian sex steroids into a subendometrial layer or junctional zone and an outer myometrial layer. Compared to the outer myometrial layer, the junctional zone myocytes are characterized by higher cellular density and lower cytoplasmic-nuclear ratio. These structural differences allow in-vivo visualization of the myometrial zonal anatomy by T2-weighted magnetic resonance (MR) imaging. The human myometrium is also functionally polarized. Video-vaginosonography studies have shown that propagated myometrial contractions in the non-pregnant uterus originate only from the junctional zone and that the frequency and orientation of these contraction waves are dependent on the phase of the menstrual cycle. The mechanisms underlying zonal myometrial differentiation are not known, but growing evidence suggests that ovarian hormone action may be mediated through cytokines and uterotonins locally released by the basal endometrial layer and endometrio-myometrial T-lymphocytes. Irregular thickening of the junctional zone due to inordinate proliferation of the inner myometrium, junctional zone hyperplasia, is a common MR finding in women suffering from menstrual dysfunction. Preliminary data suggest that junctional zone hyperplasia is further characterized by loss of normal inner myometrial function. Although irregular thickening of the junctional zone has been associated with diffuse uterine adenomyosis, the precise relationship between subendometrial smooth muscle proliferation and myometrial invasion by endometrial glands and stroma remains to be established.
人类非妊娠子宫肌层会对卵巢性类固醇产生反应，分化为子宫内膜下层或交界区以及外层子宫肌层。与外层子宫肌层相比，交界区肌细胞的特点是细胞密度较高，细胞质与细胞核的比例较低。这些结构差异使得通过T2加权磁共振（MR）成像能够在体内观察子宫肌层的分层解剖结构。人类子宫肌层在功能上也是极化的。阴道超声检查研究表明，非妊娠子宫中传播的子宫肌层收缩仅起源于交界区，并且这些收缩波的频率和方向取决于月经周期的阶段。子宫肌层分层分化的潜在机制尚不清楚，但越来越多的证据表明，卵巢激素的作用可能是通过基底层子宫内膜和子宫内膜-子宫肌层T淋巴细胞局部释放的细胞因子和子宫收缩素介导的。由于内层子宫肌层过度增殖导致交界区不规则增厚，即交界区增生，是月经功能障碍女性常见的磁共振成像表现。初步数据表明，交界区增生的进一步特征是正常内层子宫肌层功能丧失。虽然交界区不规则增厚与弥漫性子宫腺肌病有关，但子宫内膜下层平滑肌增殖与子宫内膜腺体和间质对子宫肌层的侵袭之间的确切关系仍有待确定。
