Suppressive effect of neonatal treatment with a phytoestrogen, coumestrol, on lordosis and estrous cycle in female rats

Tom Kouki, Miho Okamoto, Shizuko Wada, Miki Kishitake, Korehito Yamanouchi

Research output: Contribution to journalArticle

40 Citations (Scopus)

Abstract

The neural control systems for the ovulatory cycle and lordosis behavior are sexually differentiated by estrogen during the perinatal period in rats. In the present study, the effects of a single neonatal injection with the phytoestrogen, coumestrol, on female reproductive functions were investigated. Female rats were injected subcutaneously with 1 or 3 mg coumestrol (CM1, CM3), 1 mg genistein (GS1), 1 mg estradiol (E 2), or oil at day 5 after birth (birth day = day 1) and an estrous cycle check and lordosis behavior test were performed. As a result, vaginal opening was advanced in CM1-, CM3- or E 2-treated females. A vaginal smear check indicated that oil- or GS1-treated females showed a constant 4- or 5-day estrous cycle, whereas CM1-, CM3- or E 2-treated rats showed a persistent or prolonged estrus. Ovariectomy was performed in all females at 60 days of age. The ovary weights in the CM1-, CM3- or E 2-treated groups were lower than those in the oil- and GS1-treated groups and no corpora lutea were found in any rats of these three groups, except for two E 2-treated rats. Behavioral tests were carried out after implantation of E 2-tubes. All rats in the CM1-, GS1-treated groups showed a high lordosis quotient (LQ), being comparable to that in the oil-treated females. On the other hand, LQs in the CM3, E 2 or male groups were lower than that in the control female group. These results suggest that a single neonatal injection of 3 mg coumestrol was effective in suppressing the functions of ovulation-inducing mechanisms and the induction of lordosis, but 1 mg coumestrol was effective in only the estrous cycle of female rats.

Original languageEnglish
Pages (from-to)449-454
Number of pages6
JournalBrain Research Bulletin
Volume64
Issue number5
DOIs
Publication statusPublished - 2005 Jan 15

Fingerprint

Coumestrol
Phytoestrogens
Lordosis
Estrous Cycle
Oils
Therapeutics
Parturition
Vaginal Smears
Injections
Genistein
Corpus Luteum
Estrus
Ovariectomy
Ovulation
Ovary
Estradiol
Estrogens
Weights and Measures

Keywords

  • Brain
  • Coumestrol
  • Estrous cycle
  • Lordosis
  • Phytoestrogen
  • Rat
  • Sex differentiation

ASJC Scopus subject areas

  • Neuroscience(all)

Cite this

Suppressive effect of neonatal treatment with a phytoestrogen, coumestrol, on lordosis and estrous cycle in female rats. / Kouki, Tom; Okamoto, Miho; Wada, Shizuko; Kishitake, Miki; Yamanouchi, Korehito.

In: Brain Research Bulletin, Vol. 64, No. 5, 15.01.2005, p. 449-454.

Research output: Contribution to journalArticle

Kouki, Tom ; Okamoto, Miho ; Wada, Shizuko ; Kishitake, Miki ; Yamanouchi, Korehito. / Suppressive effect of neonatal treatment with a phytoestrogen, coumestrol, on lordosis and estrous cycle in female rats. In: Brain Research Bulletin. 2005 ; Vol. 64, No. 5. pp. 449-454.
@article{71f74b5e0186489ba745f256a83f7ef3,
title = "Suppressive effect of neonatal treatment with a phytoestrogen, coumestrol, on lordosis and estrous cycle in female rats",
abstract = "The neural control systems for the ovulatory cycle and lordosis behavior are sexually differentiated by estrogen during the perinatal period in rats. In the present study, the effects of a single neonatal injection with the phytoestrogen, coumestrol, on female reproductive functions were investigated. Female rats were injected subcutaneously with 1 or 3 mg coumestrol (CM1, CM3), 1 mg genistein (GS1), 1 mg estradiol (E 2), or oil at day 5 after birth (birth day = day 1) and an estrous cycle check and lordosis behavior test were performed. As a result, vaginal opening was advanced in CM1-, CM3- or E 2-treated females. A vaginal smear check indicated that oil- or GS1-treated females showed a constant 4- or 5-day estrous cycle, whereas CM1-, CM3- or E 2-treated rats showed a persistent or prolonged estrus. Ovariectomy was performed in all females at 60 days of age. The ovary weights in the CM1-, CM3- or E 2-treated groups were lower than those in the oil- and GS1-treated groups and no corpora lutea were found in any rats of these three groups, except for two E 2-treated rats. Behavioral tests were carried out after implantation of E 2-tubes. All rats in the CM1-, GS1-treated groups showed a high lordosis quotient (LQ), being comparable to that in the oil-treated females. On the other hand, LQs in the CM3, E 2 or male groups were lower than that in the control female group. These results suggest that a single neonatal injection of 3 mg coumestrol was effective in suppressing the functions of ovulation-inducing mechanisms and the induction of lordosis, but 1 mg coumestrol was effective in only the estrous cycle of female rats.",
keywords = "Brain, Coumestrol, Estrous cycle, Lordosis, Phytoestrogen, Rat, Sex differentiation",
author = "Tom Kouki and Miho Okamoto and Shizuko Wada and Miki Kishitake and Korehito Yamanouchi",
year = "2005",
month = "1",
day = "15",
doi = "10.1016/j.brainresbull.2004.10.002",
language = "English",
volume = "64",
pages = "449--454",
journal = "Brain Research Bulletin",
issn = "0361-9230",
publisher = "Elsevier Inc.",
number = "5",

}

TY - JOUR

T1 - Suppressive effect of neonatal treatment with a phytoestrogen, coumestrol, on lordosis and estrous cycle in female rats

AU - Kouki, Tom

AU - Okamoto, Miho

AU - Wada, Shizuko

AU - Kishitake, Miki

AU - Yamanouchi, Korehito

PY - 2005/1/15

Y1 - 2005/1/15

N2 - The neural control systems for the ovulatory cycle and lordosis behavior are sexually differentiated by estrogen during the perinatal period in rats. In the present study, the effects of a single neonatal injection with the phytoestrogen, coumestrol, on female reproductive functions were investigated. Female rats were injected subcutaneously with 1 or 3 mg coumestrol (CM1, CM3), 1 mg genistein (GS1), 1 mg estradiol (E 2), or oil at day 5 after birth (birth day = day 1) and an estrous cycle check and lordosis behavior test were performed. As a result, vaginal opening was advanced in CM1-, CM3- or E 2-treated females. A vaginal smear check indicated that oil- or GS1-treated females showed a constant 4- or 5-day estrous cycle, whereas CM1-, CM3- or E 2-treated rats showed a persistent or prolonged estrus. Ovariectomy was performed in all females at 60 days of age. The ovary weights in the CM1-, CM3- or E 2-treated groups were lower than those in the oil- and GS1-treated groups and no corpora lutea were found in any rats of these three groups, except for two E 2-treated rats. Behavioral tests were carried out after implantation of E 2-tubes. All rats in the CM1-, GS1-treated groups showed a high lordosis quotient (LQ), being comparable to that in the oil-treated females. On the other hand, LQs in the CM3, E 2 or male groups were lower than that in the control female group. These results suggest that a single neonatal injection of 3 mg coumestrol was effective in suppressing the functions of ovulation-inducing mechanisms and the induction of lordosis, but 1 mg coumestrol was effective in only the estrous cycle of female rats.

AB - The neural control systems for the ovulatory cycle and lordosis behavior are sexually differentiated by estrogen during the perinatal period in rats. In the present study, the effects of a single neonatal injection with the phytoestrogen, coumestrol, on female reproductive functions were investigated. Female rats were injected subcutaneously with 1 or 3 mg coumestrol (CM1, CM3), 1 mg genistein (GS1), 1 mg estradiol (E 2), or oil at day 5 after birth (birth day = day 1) and an estrous cycle check and lordosis behavior test were performed. As a result, vaginal opening was advanced in CM1-, CM3- or E 2-treated females. A vaginal smear check indicated that oil- or GS1-treated females showed a constant 4- or 5-day estrous cycle, whereas CM1-, CM3- or E 2-treated rats showed a persistent or prolonged estrus. Ovariectomy was performed in all females at 60 days of age. The ovary weights in the CM1-, CM3- or E 2-treated groups were lower than those in the oil- and GS1-treated groups and no corpora lutea were found in any rats of these three groups, except for two E 2-treated rats. Behavioral tests were carried out after implantation of E 2-tubes. All rats in the CM1-, GS1-treated groups showed a high lordosis quotient (LQ), being comparable to that in the oil-treated females. On the other hand, LQs in the CM3, E 2 or male groups were lower than that in the control female group. These results suggest that a single neonatal injection of 3 mg coumestrol was effective in suppressing the functions of ovulation-inducing mechanisms and the induction of lordosis, but 1 mg coumestrol was effective in only the estrous cycle of female rats.

KW - Brain

KW - Coumestrol

KW - Estrous cycle

KW - Lordosis

KW - Phytoestrogen

KW - Rat

KW - Sex differentiation

UR - http://www.scopus.com/inward/record.url?scp=10644256585&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=10644256585&partnerID=8YFLogxK

U2 - 10.1016/j.brainresbull.2004.10.002

DO - 10.1016/j.brainresbull.2004.10.002

M3 - Article

C2 - 15607833

AN - SCOPUS:10644256585

VL - 64

SP - 449

EP - 454

JO - Brain Research Bulletin

JF - Brain Research Bulletin

SN - 0361-9230

IS - 5

ER -