Structural and functional evidence for the denervation of human myometrium during pregnancy

The neuronal influence of the contractility of the term-pregnant human uterus was studied by pharmacologic and histochemical methods. By the use of adrenergic and cholinergic antagonists or tetrodotoxin it was demonstrated that the contractile response of superfused myometrial strips from the term-pregnant uterus to electrofield stimulation was not influenced by any neuronal factor. Using an indirect immunofluorescence technique with an antiserum to the glial and Schwann cell specific S-100 protein, a marked paucity of nerve fibers was demonstrated in myometrial strips from the term-pregnant uterus as compared with the nonpregnant uterus. It is concluded that the described decrease of nerve fibers within the myometrium of the pregnant uterus may be of importance for the myometrial activity during pregnancy and parturition.