Catecholamines and gonadotropin secretion in sterile women.

We studied changes in catecholamines, as related to estrogen positive feedback mechanisms, and we measured two catecholamine metabolites (DOPAC, MHPG) in the plasma, using high performance liquid chromatography. In the case of the mean MHPG level, the mean values for two groups in which LH levels were from 100 to 200 percent of the basal level of LH and under the basal level of LH were significantly higher than that of a group in which the LH level was double the value for the basal level of LH. But the mean basal DOPAC level showed no significant difference among the three groups. In the good LH reaction group, the MHPG level at 24 and 48 hours after estrogen injection was significantly higher than the mean basal MHPG level. But in other two groups, the mean MHPG levels showed no significant differences. In the case of DOPAC, there was no significant difference in any group. All these observations taken together suggested that in vivo, catecholamines may influence the secretion of gonadotropins.