delta9-Tetrahydrocannabinol and 17beta-estradiol bind to different macromolecules in estrogen target tissues.
delta9-Tetrahydrocannabinol (delta9-THC), added to the limit of its solubility, did not compete with tritiated 17beta-estradiol for binding to estrogen receptor sites in mouse mammary or uterine cytosols. On sucrose density gradients of low-ionic strength, mammary cytosol labeled with [3H]estradiol exhibited a binding peak near the "8S" region typical of estrogen receptor whereas in cytosol labeled with delta9-[3H]THC binding was limited to the nonspecific 4- to 5S region. Differences in sedimentation properties and reciprocal competition studies strongly refute previous claims that delta-9-THC binds to estrogen receptor and that by so doing it directly acts as an estrogen.
D000818:Animals; D001667:Binding, Competitive; D003600:Cytosol / Q000378:metabolism; D013759:Dronabinol / Q000378:metabolism*; D004958:Estradiol / Q000378:metabolism*; D005260:Female; D008321:Mammary Glands, Animal / Q000378:metabolism; D051379:Mice; D008970:Molecular Weight; D011955:Receptors, Drug / Q000378:metabolism*; D011960:Receptors, Estrogen / Q000302:isolation & purification / Q000378:metabolism*; D014599:Uterus / Q000378:metabolism
D011955:Receptors, Drug; D011960:Receptors, Estrogen; D004958:Estradiol; D013759:Dronabinol