“…PGF-2ais now believed to be the uterine luteolytic agent in most species except primates (see Horton & Poyser, 1976, for review). Human luteal function appears to be independent of uterine control since neither hysterectomy (Beling, Marcus & Markham, 1970) nor congenital absence of Fallopian tubes, uterus and vagina (Fraser, Baird, Hobson, Michie & Hunter, 1973) disrupt cyclic ovarian function. PGF-2a in vitro, however, in cultured human granulosa cells (McNatty, Henderson & Sawers, 1975), or directly injected into the human ovary (Korda, Shutt, Smith, Shearman & Lyneham, 1975) reduces progesterone secretion, suggesting a possible intraovarian role for in man.…”