Preterm labour. Myometrial function in prematurity.
The primary function of the uterus during gestation is to harbour the growing conceptus in a largely quiescent environment. Upon maturation of the fetus to a point sufficient for extrauterine survival, the uterus must remodel itself sufficiently to generate forceful contractions during labour. During preterm delivery, the process of remodelling of the myometrium occurs early due to a number of different causes, although the underlying basis for myometrial contraction remains the same. This review summarises the anatomical, physiological and molecular basis for contraction. We describe the fibre structure of the human uterus and how this relates to the spread of electrical excitation during a contraction. The process of excitation within a single myometrial cell is described, as well as how this relates to contraction. We then focus on how excitation-contraction coupling is modulated by intercellular communication, pharmacomechanical-coupling and hormonal milieu. Lastly, we consider the actions of the commonly accepted uterine agonists oxytocin, prostaglandin F(2alpha), and prostaglandin E(2), and the tocolytic ritodrine.
Blanks
Andrew M
AM
Clinical Sciences Research Institute, University of Warwick, University Hospitals of Coventry and Warwickshire, Clifford Bridge Road, Coventry CV2 2DX, UK. Andrew.Blanks@warwick.ac.uk
Shmygol
Anatoly
A
Thornton
Steven
S
D005260:Female; D006801:Humans; D009215:Myometrium / Q000502:physiology*; D007752:Obstetric Labor, Premature / Q000378:metabolism / Q000503:physiopathology*; D010121:Oxytocin / Q000502:physiology; D011247:Pregnancy; D018045:Receptors, Oxytocin / Q000378:metabolism; D012312:Ritodrine / Q000494:pharmacology; D015149:Tocolytic Agents / Q000494:pharmacology; D014590:Uterine Contraction / Q000502:physiology*
D018045:Receptors, Oxytocin; D015149:Tocolytic Agents; D010121:Oxytocin; D012312:Ritodrine