PMID- 33321143
OWN - NLM
STAT- MEDLINE
DCOM- 20210618
LR  - 20210618
IS  - 1873-507X (Electronic)
IS  - 0031-9384 (Linking)
VI  - 230
DP  - 2021 Mar 1
TI  - Why does castrated male odor attract sexually active male rats?-Attractivity 
      induced by hypothalamus-pituitary-gonad axis block.
PG  - 113288
LID - S0031-9384(20)30602-8 [pii]
LID - 10.1016/j.physbeh.2020.113288 [doi]
AB  - Sexually experienced male rats show an olfactory preference for estrous female 
      odor compared to male odor. Notably, they also prefer castrated male over 
      gonadally intact male odor. This study examined the role of elevated circulating 
      gonadotropins and gonadotropin-releasing hormone (GnRH) induced by disinhibition 
      of the hypothalamus-pituitary-gonad axis in the castration-induced attractiveness 
      of male rats. Experiment I compared preference of sexually experienced males 
      between odors of castrated males injected with a GnRH antagonist (Cast+Ant), 
      castrated males injected with saline (Cast), and gonadally intact males (Sham). 
      These olfactory preference tests revealed that probe males significantly 
      preferred Cast over Sham and Cast+Ant odors but had no preference between Sham 
      and Cast+Ant odors. Experiment II used hypophysectomy (HPx) to remove the 
      gonadotropin source in place of pharmacologically antagonizing GnRH. Similarly, 
      the probe males preferred Cast (high both GnRH and gonadotropins) over HPx (high 
      GnRH but no gonadotropin) odors, but also preferred HPx than Sham (low both GnRH 
      and gonadotropins) odors. We then examined the effects of exogenous 
      gonadotropins, human chorionic gonadotropin (hCG) and equine chorionic 
      gonadotropin (eCG), to reveal which gonadotropins critically affect on the 
      attractiveness of HPx males. The olfactory preference tests revealed that 
      injecting eCG, but not hCG, significantly increased the probe males; preference 
      compared to HPx male odor, suggesting that the attractiveness is augmented via 
      follicle stimulating hormone (FSH) receptor rather than luteinizing hormone 
      receptor. These results indicate that sexually active male rats show olfactory 
      preference for castrated male rats due to elevated GnRH and FSH blood levels 
      produced by a lack of androgens.
CI  - Copyright (c) 2020 Elsevier Inc. All rights reserved.
FAU - Hayashi, Himeka
AU  - Hayashi H
AD  - Department of Animal Sciences, Teikyo University of Science, 2525 Yatsusawa, 
      Uenohara, Yamanashi 409-0193, Japan.
FAU - Kumagai, Ryoko
AU  - Kumagai R
AD  - Department of Animal Sciences, Teikyo University of Science, 2525 Yatsusawa, 
      Uenohara, Yamanashi 409-0193, Japan.
FAU - Kondo, Yasuhiko
AU  - Kondo Y
AD  - Department of Animal Sciences, Teikyo University of Science, 2525 Yatsusawa, 
      Uenohara, Yamanashi 409-0193, Japan. Electronic address: ykondo@ntu.ac.jp.
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
DEP - 20201213
PL  - United States
TA  - Physiol Behav
JT  - Physiology & behavior
JID - 0151504
RN  - 33515-09-2 (Gonadotropin-Releasing Hormone)
RN  - 9002-67-9 (Luteinizing Hormone)
RN  - 9002-68-0 (Follicle Stimulating Hormone)
SB  - IM
MH  - Animals
MH  - Female
MH  - *Follicle Stimulating Hormone
MH  - Gonadotropin-Releasing Hormone/metabolism
MH  - Gonads
MH  - Horses
MH  - Hypothalamus/metabolism
MH  - *Luteinizing Hormone
MH  - Male
MH  - Odorants
MH  - Pituitary Gland/metabolism
MH  - Rats
OTO - NOTNLM
OT  - Gonadotropin-releasing hormone, follicle stimulating hormone, pituitary
OT  - Olfactory preference
OT  - Sexual attraction
EDAT- 2020/12/16 06:00
MHDA- 2021/06/22 06:00
CRDT- 2020/12/15 20:08
PHST- 2020/10/01 00:00 [received]
PHST- 2020/12/10 00:00 [revised]
PHST- 2020/12/10 00:00 [accepted]
PHST- 2020/12/16 06:00 [pubmed]
PHST- 2021/06/22 06:00 [medline]
PHST- 2020/12/15 20:08 [entrez]
AID - S0031-9384(20)30602-8 [pii]
AID - 10.1016/j.physbeh.2020.113288 [doi]
PST - ppublish
SO  - Physiol Behav. 2021 Mar 1;230:113288. doi: 10.1016/j.physbeh.2020.113288. Epub 
      2020 Dec 13.