title: Transient reversal of olfactory preference following castration in male rats: Implication for estrogen receptor involvement.
abstract: We examined the effects of the sex steroid milieu on sexual odor preference of sexually-experienced male rats using an alternate choice paradigm after endocrine manipulations. Gonadally intact (GI) males showed a male typical preference, i.e. spent longer time sniffing estrous females than males or ovariectomized females. At 1-2 weeks after orchidectomy (ORx), the males exhibited a transient preference for sexually vigorous males, a female typical preference pattern, followed by a total loss of preference after 4 weeks. Subcutaneous implantation of a Silastic capsule containing formestane (4-OHA), an aromatase inhibitor, had no effect on the preference of gonadally intact rats, but successfully prevented the emergence of the female typical preference after ORx. Capsules containing testosterone (T), dihydrotestosterone (DHT), or estradiol benzoate (EB), but not those with cholesterol (CH), restored masculine typical preference in ORx males at 2 weeks after the placement. The feminine preference for males was observed at 2-3 weeks after removal of T or EB capsules, but not by the removal of DHT and CH capsules. The results suggest that either exogenous androgen or estrogen maintains the masculine typical odor preference. Estrogen itself or produced through aromatization of circulating T, induces a transient feminine typical preference at a certain decreased titer during its disappearance from the circulation. Estrogen at different titers might determine appearance of masculine or feminine typical olfactory preference in adult ORx rats.
authors.affiliation: Department of Physiology, Nippon Medical School, Tokyo 113-8602, Japan.
authors.forename: Kai
authors.initials: K
authors.lastname: Xiao
authors.affiliation: Department of Material and Life Sciences, Sophia University, Tokyo 102-8554, Japan.
authors.forename: Atsuhiko
authors.initials: A
authors.lastname: Chiba
authors.affiliation: Department of Physiology, Nippon Medical School, Tokyo 113-8602, Japan.
authors.forename: Yasuo
authors.initials: Y
authors.lastname: Sakuma
authors.affiliation: Department of Physiology, Nippon Medical School, Tokyo 113-8602, Japan; Department of Animal Sciences, Teikyo University of Science, Tokyo 120-0045, Japan. Electronic address: ykondo@ntu.ac.jp.
authors.forename: Yasuhiko
authors.initials: Y
authors.lastname: Kondo
mesh_terms: D000728:Androgens / Q000008:administration & dosage; D000818:Animals; D002784:Cholesterol / Q000008:administration & dosage; D013196:Dihydrotestosterone / Q000008:administration & dosage; D004958:Estradiol / Q000008:administration & dosage / Q000031:analogs & derivatives; D004967:Estrogens / Q000008:administration & dosage; D005260:Female; D008297:Male; D009812:Odorants; D055696:Olfactory Perception / Q000187:drug effects / Q000502:physiology*; D009919:Orchiectomy; D010812:Physical Stimulation; D011619:Psychotropic Drugs / Q000008:administration & dosage; D020318:Rats, Long-Evans; D011960:Receptors, Estrogen / Q000378:metabolism*; D012726:Sexual Behavior, Animal / Q000187:drug effects / Q000502:physiology*; D013739:Testosterone / Q000008:administration & dosage
chemical_list: D000728:Androgens; D004967:Estrogens; D011619:Psychotropic Drugs; D011960:Receptors, Estrogen; D013196:Dihydrotestosterone; C074283:estradiol 3-benzoate; D013739:Testosterone; D004958:Estradiol; D002784:Cholesterol
keywords: Androgen; Aromatase; Estrogen; Olfactory preference; Receptors; Sexual behavior