Spontaneous Contractions of the Human Ovary in Vitro

The mechanism controlling the last step in ovulation—ejection of the follicular contents—is not yet fully explained. Several hypotheses have been proposed, for example, increased intrafollicular pressure (Bartelmez, 1912; Smith, 1934; Jensen & Zacharia, 1960), contractions of the follicular wall (Lipner & Maxwell, 1960), and enzymatic breakdown (digestion) of the follicular wall (Espey & Lipner, 1965; Espey, 1967; Espey, Slagter, Weymouth & Rondell, 1965; Espey & Rondell, 1968; Rondell, 1970) but none has been proven to be the mechanism of ovulation. However, it is agreed by all that a fully developed stigma is essential for ovulation. Recently, spontaneous contractions of cat ovaries in vitro were demonstrated and a response to adrenergic drugs was shown (Rocereto, Jacobowitz & Wallach, 1969). These contractions were assumed to be under the control of sympathetic impulses mediated through the adrenergic innervation (Jacobowitz & Wallach, 1967; Rocereto et al., 1969) to the smooth muscle cells found in