title: The inhibitory effect of dopamine agonists on LH release in women.
abstract: Our demonstration of an inhibitory effect of dopamine on LH release prompted us to examine whether a similar action exists for dopamine agonists, such as L-dopa and 2-bromo-alpha-ergocryptine (CB-154). Following the administration of L-dopa (0.5 g, orally) to 6 normal women in the early follicular phase, a significant fall in mean LH levels after 1 h which lasted for 5 h was observed (P less than 0.00005). This was followed by a significant rebound above basal levels between the 7th and 10th h (P less than 0.00005). The expected fall in mean PRL levels which lasted for 4 h (P less than 0.00001) was followed by a significant rebound above basal levels after the  6th h (P less than 0.00001)). There was no significant change in mean FSH levels. Following the administration of CB-154 (2.5 mg. orally) to 6 women with hyperprolactinemic amenorrhea, there was also a significant fall in LH levels (P less than 0.00001) and in FSH levels (P less than 0.00001) from 5 h until the study ended at 10 h. The anticipated PRL suppression was also observed and persisted for the duration of the 10 h study. The demonstration of an inhibitory effect of L-dopa and CB-154 on LH release adds further support to the role of dopaminergic control of pituitary LH secretion.
mesh_terms: D000568:Amenorrhea / Q000097:blood; D001971:Bromocriptine; D004873:Ergolines; D005260:Female; D005640:Follicle Stimulating Hormone / Q000097:blood; D006801:Humans; D007980:Levodopa; D007986:Luteinizing Hormone / Q000097:blood*; D011388:Prolactin / Q000097:blood
chemical_list: D004873:Ergolines; D001971:Bromocriptine; D007980:Levodopa; D011388:Prolactin; D007986:Luteinizing Hormone; D005640:Follicle Stimulating Hormone