Plasma β-endorphin level in cases of luteal phase defect

To evaluate β-endorphin secretion in euprolactinemic cases of luteal phase defect (LPD). Serial blood samples from the 18th to the 26th day of the menstrual cycle were assayed for β-endorphin, progesterone (P), estradiol (E2), and prolactin (PRL) in cases of LPD and controls. Diagnosis of LPD was based on determinations of serum P and premenstrual endometrial biopsy. From Cairo University Hospitals. Twenty-six women with LPD and 8 normal fertile women (controls) were chosen. None. β-Endorphin, P, E2, and PRL concentrations were determined by the corresponding 125I radioimmunoassay. Plasma β-endorphin level in cases of LPD varied from 2.58 to 9.14 pmol/L, whereas the level of controls varied from 2.41 to 5.57 pmol/L. The mean value of plasma β-endorphin in cases of LPD was significantly higher than that of controls by 146% (P