Specific effect of CV 205-502, a potent nonergot dopamine agonist, during a combined anterior pituitary function test.
CV 205-502, an octahydrobenzo[g]quinoline, is a dopamine agonist compound that is not an ergot or ergoline derivative. To investigate the site of action of CV 205-502, three groups of five men were given single daily doses of CV 205-502 (0.04, 0.06, or 0.08 mg/day, doses that suppress plasma PRL by 60-80% for 24 h) for 5 days; on day 6 a combined anterior pituitary function test using iv administration of four hypothalamic releasing hormones (TRH, 200 micrograms; GHRH, 100 micrograms; CRH, 100 micrograms; LHRH, 100 micrograms) was performed. One month later the challenge tests were repeated to obtain control values. The following hormones were measured by RIA in plasma: TSH, ACTH, cortisol, PRL, GH, LH, FSH, and testosterone. With the exception of plasma PRL levels, basal and releasing hormone-stimulated values were similar after CV 205-502 administration and after the 1-month washout period. Basal plasma PRL was lower after CV 205-502 administration, and the response to TRH was attenuated by all three doses of CV 205-502 (the mean percent inhibition values were 76%, 93%, and 94%, respectively). All three doses of CV 205-502 were well tolerated, and another group of men well tolerated 0.1 mg daily. The results confirm that CV 205-502 is a potent dopamine agonist, which directly inhibits lactotropic cells but has no effect on other pituitary cell types.
Gaillard
R C
RC
Department of Medicine, University Hospital, Geneva, Switzerland.
Abeywickrama
K
K
Brownell
J
J
Muller
A F
AF
D000328:Adult; D000634:Aminoquinolines / Q000494:pharmacology*; D001665:Binding Sites; D003346:Corticotropin-Releasing Hormone / Q000494:pharmacology; D015259:Dopamine Agents / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D007987:Gonadotropin-Releasing Hormone / Q000494:pharmacology; D013007:Growth Hormone-Releasing Hormone / Q000494:pharmacology; D006801:Humans; D007031:Hypothalamus / Q000187:drug effects / Q000502:physiology; D008297:Male; D010901:Pituitary Function Tests; D010903:Pituitary Gland, Anterior / Q000187:drug effects / Q000502:physiology*; D010908:Pituitary Hormones, Anterior / Q000097:blood; D011388:Prolactin / Q000097:blood; D011954:Receptors, Dopamine / Q000187:drug effects; D013739:Testosterone / Q000097:blood; D013973:Thyrotropin-Releasing Hormone / Q000494:pharmacology
D000634:Aminoquinolines; D015259:Dopamine Agents; D010908:Pituitary Hormones, Anterior; D011954:Receptors, Dopamine; D007987:Gonadotropin-Releasing Hormone; D013739:Testosterone; D013973:Thyrotropin-Releasing Hormone; C046650:quinagolide; D011388:Prolactin; D003346:Corticotropin-Releasing Hormone; D013007:Growth Hormone-Releasing Hormone