PMID- 8828584
OWN - NLM
STAT- MEDLINE
DCOM- 19961206
LR  - 20190614
IS  - 0006-8993 (Print)
IS  - 0006-8993 (Linking)
VI  - 725
IP  - 1
DP  - 1996 Jun 24
TI  - Sex differences in estrogen receptor and progestin receptor induction in the 
      guinea pig hypothalamus and preoptic area.
PG  - 37-48
AB  - Quantitative in vitro autoradiography was used to determine if regional sex 
      differences in estrogen receptor (ER) content and/or estrogen responsiveness, as 
      indicated by an increase in progestin receptor (PR), are present in the adult 
      guinea pig brain. Adult male and female guinea pigs were gonadectomized 1 week 
      before subcutaneous injection of 25 micrograms estradiol benzoate (EB)/kg body wt 
      or the sesame oil vehicle. Animals were killed by decapitation 44 h after 
      injection. Unoccupied PRs, and unoccupied and occupied ERs, were measured in 
      discrete brain regions by quantitative in vitro autoradiography using [3H]R5020 
      and [3H]estradiol as ligands, respectively. In vehicle-injected controls, a 
      higher level of ER was found in the arcuate nucleus (ARC), dorsal medial nucleus 
      (DMN) and ventrolateral nucleus (VLN) of females as compared to males. At 44 h 
      after EB injection, 32-55% of the ERs were occupied; however, EB treatment caused 
      a marked down-regulation of total receptor (calculated as occupied+ unoccupied 
      receptor) in most of the brain regions examined, including the periventricular 
      preoptic area (PVP), medial preoptic area (MPO), bed nucleus of the stria 
      terminalis, paraventricular nucleus, ARC, ventrolateral hypothalamus (VLH), VLN, 
      and DMN. In EB-treated animals, PR binding was detectable in the PVP, MPO, ARC, 
      VLH, and VLN, with higher levels of binding observed in the PVP, MPO, and VLN of 
      the female as compared to the male. No PR binding was observed in oil-injected 
      control animals. These results demonstrate region-specific sex differences in ER 
      as well as estrogen-induced regulation of progestin and ERs in the guinea pig 
      brain. The discordance between the regional distributions of sex differences in 
      ER and estrogen-induced PR implies that sex differences in ER and 
      estrogen-induced PR implies that sex differences in estrogen response may not be 
      clearly linked to a sex difference in receptor number. Instead, sex differences 
      in response may involve differences in receptor number within specific 
      subpopulations of estrogen target cells or may involve differences in ER 
      dynamics.
FAU - Brown, T J
AU  - Brown TJ
AD  - Division of Reproductive Science, Toronto Hospital Research Institute, Ont., 
      Canada. ted.brown@utoronto.ca
FAU - Yu, J
AU  - Yu J
FAU - Gagnon, M
AU  - Gagnon M
FAU - Sharma, M
AU  - Sharma M
FAU - MacLusky, N J
AU  - MacLusky NJ
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
PL  - Netherlands
TA  - Brain Res
JT  - Brain research
JID - 0045503
RN  - 0 (Receptors, Estrogen)
RN  - 0 (Receptors, Progesterone)
RN  - 4TI98Z838E (Estradiol)
SB  - IM
MH  - Animals
MH  - Autoradiography
MH  - Binding, Competitive
MH  - Estradiol/*pharmacology
MH  - Female
MH  - Guinea Pigs
MH  - Hypothalamus/*physiology
MH  - Male
MH  - Preoptic Area/*physiology
MH  - Receptors, Estrogen/*drug effects
MH  - Receptors, Progesterone/*drug effects
MH  - Sex Characteristics
EDAT- 1996/06/24 00:00
MHDA- 1996/06/24 00:01
CRDT- 1996/06/24 00:00
PHST- 1996/06/24 00:00 [pubmed]
PHST- 1996/06/24 00:01 [medline]
PHST- 1996/06/24 00:00 [entrez]
AID - 0006-8993(96)00241-7 [pii]
AID - 10.1016/0006-8993(96)00241-7 [doi]
PST - ppublish
SO  - Brain Res. 1996 Jun 24;725(1):37-48. doi: 10.1016/0006-8993(96)00241-7.