title: Dispersal of estradiol-17 beta from the site of injection in the pectoral muscles of Japanese quail.
abstract: Exogenous estrogens, if given in sufficient quantity, stimulate vitellogenesis in the males of vitellogenic species. In the present study, ethanolic solutions of estradiol-17 beta (E2), labeled with 16-alpha-[125I]iodoestradiol ([125I]E2) or sodium iodide (Na125I), were injected into the pectoral muscles of male Japanese quail. The rate of dispersal of the estradiol from the site of injection was measured in vivo during 4 days. The curves of radioactivity appeared to be diphasic. The dose percentages forming the second phase of these curves and the half-time for the second phase were: for 16 mumol E2 ([125I]E2 label)/100 g body weight, 84.6% and 27.6 hr; for 6 pmol [125I]E2/100 g, 20.0% and 17.2 hr; for 16 mumol E2 (Na125I label)/100 g, 6.7% and 99.0 hr, and for Na125I, 6.1% and 83.1 hr. Thus, in male quail the estradiol-induced stimulation of vitellogenesis apparently resulted from a continuing hormonal pressure on the liver during the period of study and not from a rapid flow of E2 to the liver shortly after injection.
mesh_terms: D000818:Animals; D003370:Coturnix; D004625:Embryo, Nonmammalian / Q000378:metabolism; D004958:Estradiol / Q000008:administration & dosage* / Q000378:metabolism; D005260:Female; D007273:Injections, Intramuscular; D007457:Iodine Radioisotopes; D007700:Kinetics; D008297:Male; D009132:Muscles / Q000378:metabolism*
chemical_list: D007457:Iodine Radioisotopes; D004958:Estradiol