The depletion of plasma prolactin by pantethine in oestrogen-primed hyperprolactinaemic rats.
Pantethine was investigated for its potential to deplete prolactin in the plasma and pituitary cells of oestrogen-primed hyperprolactinaemic rats. This compound has been used in the past to deliver cysteamine systemically, through its congener pantetheine, a metabolic precursor for cysteamine. Cysteamine itself, specifically reduces plasma and pituitary prolactin. The addition of pantethine (2-10 mmol/l) to the media of isolated pituitary cells over 4 h did not appreciably alter the intracellular content of immunoreactive prolactin. Moreover, oral administration of pantethine at 0.5 and 1.0 g/kg body weight did not influence the concentration of immunoreactive plasma prolactin. However, the concentration of plasma prolactin fell by 48 and 67%, when pantethine was injected i.p. at 0.5 and 1.0 g/kg body weight, after 4 h. Intravenous administration of pantethine resulted in even greater losses of prolactin, in the order of 50 and 81% depletion for 0.5 and 1.0 g/kg body weight respectively and within 2 h of administration. However, cysteamine was found to be more efficacious than pantethine on a molar basis with regard to depleting the plasma concentration of prolactin in hyperprolactinaemic rats.
Jeitner
T M
TM
Department of Physiology, Flinders Medical Centre, Bedford Park, South Australia.
Oliver
J R
JR
D000284:Administration, Oral; D000818:Animals; D003543:Cysteamine / Q000627:therapeutic use; D004958:Estradiol / Q000031:analogs & derivatives; D006966:Hyperprolactinemia / Q000139:chemically induced / Q000188:drug therapy*; D066298:In Vitro Techniques; D007274:Injections, Intraperitoneal; D007275:Injections, Intravenous; D008297:Male; D010204:Pantetheine / Q000008:administration & dosage / Q000031:analogs & derivatives / Q000627:therapeutic use*; D010902:Pituitary Gland / Q000187:drug effects; D011388:Prolactin / Q000097:blood*; D051381:Rats; D013438:Sulfhydryl Compounds / Q000627:therapeutic use*
D013438:Sulfhydryl Compounds; D010204:Pantetheine; D004958:Estradiol; D003543:Cysteamine; C005425:pantethine; D011388:Prolactin; C010452:estradiol-17 beta-benzoate