Activation of the hypothalamus-pituitary-adrenal (HPA) axis is suggested to play a role in the stress-related inhibition of LH secretion. The aim of our study was to investigate the effects of vasopressin and oxytocin, which are increased in pituitary portal plasma in response to stress, and of glucocorticoids, the final product of HPA activation during stress, on basal plasma LH levels and on pituitary LH response to the GnRH test in amenorrheic (n = 33) and fertile (n = 13) women. Plasma LH levels were evaluated by radioimmunoassay in 2 different experimental conditions: 1. Basal secretion; 2. The GnRH test (10 micrograms + 10 micrograms after a 120-minute interval). These 2 evaluations were done in the presence of both placebo and a pharmacological dose of desmopressin (an analogue of vasopressin) (16.6 ngr/minute), oxytocin (0.2 ngr/minute) or hydrocortisone (4.1 mg/minute). None of these drugs modified basal plasma LH levels either in amenorrheic patients or in controls. Hydrocortisone inhibited the GnRH-induced LH increase in amenorrheic women. These data suggest that the glucocorticoids might play a role in LH secretion and indicate a possible participation of the HPA axis in the impairment of the hypothalamus-pituitary-gonadal axis in women with psychogenic amenorrhea.