Role of progesterone receptors during postpartum estrus in rats.
We studied the role of progesterone receptor (PR) in the display of female sexual behavior during postpartum estrus in rats. Adult female rats were treated with the PR antagonist, RU486 (1.25 and 5 mg), 3 h after parturition and sexual behavior was evaluated throughout the first postpartum day. Estradiol and progesterone serum levels changed during the first 24 h postpartum. The highest estradiol and progesterone levels were found at 9 and 12 h postpartum, respectively. The predominant PR isoform in the hypothalamus and the preoptic area was PR-A during postpartum day. The content of PR-A increased at 6 h postpartum in the hypothalamus and the preoptic area, and decreased in both regions at 9 h. PR-B content only increased in the preoptic area at 12 h postpartum. The highest display of lordotic and proceptive behaviors were found at 12 h postpartum. The treatment with 1.25 and 5 mg of RU486 respectively reduced lordosis by 61% and 92% at 12 h postpartum. These results suggest that PR is essential in the display of postpartum estrus in rats.
Facultad de Química, Departamento de Biología, Universidad Nacional Autónoma de México, México DF, Mexico.
Graciela Elena
GE
Carrillo-Martínez
Porfirio
P
Gómora-Arrati
Aliesha
A
González-Arenas
Sumiko
S
Morimoto
Ignacio
I
Camacho-Arroyo
Oscar
O
González-Flores
D000704:Analysis of Variance; D000818:Animals; D015153:Blotting, Western; D004958:Estradiol / Q000097:blood; D004971:Estrus / Q000187:drug effects / Q000378:metabolism*; D005260:Female; D007031:Hypothalamus / Q000187:drug effects / Q000378:metabolism*; D015735:Mifepristone / Q000494:pharmacology; D049590:Postpartum Period / Q000187:drug effects / Q000378:metabolism*; D011187:Posture / Q000502:physiology; D011374:Progesterone / Q000097:blood; D020033:Protein Isoforms / Q000378:metabolism*; D011863:Radioimmunoassay; D051381:Rats; D017207:Rats, Sprague-Dawley; D011980:Receptors, Progesterone / Q000378:metabolism*; D012726:Sexual Behavior, Animal / Q000187:drug effects / Q000502:physiology*; D013997:Time Factors
D020033:Protein Isoforms; D011980:Receptors, Progesterone; D015735:Mifepristone; D011374:Progesterone; D004958:Estradiol