Prolactin as an inhibitor of granulosa cell luteinization: implications for hyperprolactinemia-associated luteal phase dysfunction**Supported in part by the Frank C. Bressler Research Fund and National Institutes of Health Research grant HD-19998.††Presented in part at the forty-second annual meeting of The American Fertility Society and the eighteenth annual meeting of The Canadian Fertility and Andrology Society, September 27 to October 2, 1986, Toronto, Ontario, Canada.