The onset of puberty in the female rat

changes in plasma prolactin, gonadotropins, luteinizing hormone releasing hormone (LHRH), and hypothalamic LHRH content

Sergio Ojeda, J. E. Wheaton, H. E. Jameson, S. M. McCann

Research output: Contribution to journalArticle

89 Citations (Scopus)

Abstract

In order to study the sequence of hormonal changes that accompany the onset of puberty in the female rat, immature animals were sacrificed by decapitation between days 32 and 38, and plasma titers of gonadotropins, prolactin, and LHRH, and the hypothalamic content of LHRH were determined by specific radioimmunoassays (RIA). Animals were decapitated at 10:00 and 16:00 h throughout the pubertal period, the uterine weight was recorded, and the ovaries were inspected for signs of ovulation. Animals with the vagina closed were grouped according to the condition of the uterus as anestrus (A), early proestrus (EP) and late proestrus (LP), the uterus being unstimulated, dilated with some fluid, or ballooned, respectively. Vaginal opening was usually associated with ovulation and in most cases occurred at the end of the late proestrous phase. Animals were studied up to 3 days after vaginal opening and were grouped according to vaginal cytology. Uterine weight, taken as an index of estrogen secretion, was low during A, increased during EP, and reached a peak at LP, declining thereafter. Plasma LH and FSH were low from A until the afternoon of LP. At this time, uterine weight was maximal and both gonadotropins increased dramatically. The following morning (estrus), LH, but not FSH, had returned to basal values. FSH returned to basal levels on the afternoon of estrus. Plasma prolactin was low in the morning during the entire period, but showed peaks on the afternoons, which reached a maximum at LP and declined thereafter following the pattern of changes in uterine weight. Plasma LHRH was uniformly low throughout the entire pubertal period, whereas hypothalamic LHRH content declined on the morning of estrus (day of vaginal opening). The authors suggest that the onset of puberty in the female rat is brought about by a gradual increase in estrogen secretion which, acting at the CNS pituitary level, triggers a preovulatory proestrous like surge of gonadotropins and prolactin.

Original languageEnglish (US)
Pages (from-to)630-638
Number of pages9
JournalEndocrinology
Volume98
Issue number3
StatePublished - 1976
Externally publishedYes

Fingerprint

Hypothalamic Hormones
Proestrus
Puberty
Gonadotropins
Gonadotropin-Releasing Hormone
Prolactin
Estrus
Weights and Measures
Ovulation
Uterus
Estrogens
Anestrus
Decapitation
Vagina
Radioimmunoassay
Cell Biology
Ovary

ASJC Scopus subject areas

  • Endocrinology
  • Endocrinology, Diabetes and Metabolism

Cite this

The onset of puberty in the female rat : changes in plasma prolactin, gonadotropins, luteinizing hormone releasing hormone (LHRH), and hypothalamic LHRH content. / Ojeda, Sergio; Wheaton, J. E.; Jameson, H. E.; McCann, S. M.

In: Endocrinology, Vol. 98, No. 3, 1976, p. 630-638.

Research output: Contribution to journalArticle

@article{19355bc457874811945cf3f60132ec0d,
title = "The onset of puberty in the female rat: changes in plasma prolactin, gonadotropins, luteinizing hormone releasing hormone (LHRH), and hypothalamic LHRH content",
abstract = "In order to study the sequence of hormonal changes that accompany the onset of puberty in the female rat, immature animals were sacrificed by decapitation between days 32 and 38, and plasma titers of gonadotropins, prolactin, and LHRH, and the hypothalamic content of LHRH were determined by specific radioimmunoassays (RIA). Animals were decapitated at 10:00 and 16:00 h throughout the pubertal period, the uterine weight was recorded, and the ovaries were inspected for signs of ovulation. Animals with the vagina closed were grouped according to the condition of the uterus as anestrus (A), early proestrus (EP) and late proestrus (LP), the uterus being unstimulated, dilated with some fluid, or ballooned, respectively. Vaginal opening was usually associated with ovulation and in most cases occurred at the end of the late proestrous phase. Animals were studied up to 3 days after vaginal opening and were grouped according to vaginal cytology. Uterine weight, taken as an index of estrogen secretion, was low during A, increased during EP, and reached a peak at LP, declining thereafter. Plasma LH and FSH were low from A until the afternoon of LP. At this time, uterine weight was maximal and both gonadotropins increased dramatically. The following morning (estrus), LH, but not FSH, had returned to basal values. FSH returned to basal levels on the afternoon of estrus. Plasma prolactin was low in the morning during the entire period, but showed peaks on the afternoons, which reached a maximum at LP and declined thereafter following the pattern of changes in uterine weight. Plasma LHRH was uniformly low throughout the entire pubertal period, whereas hypothalamic LHRH content declined on the morning of estrus (day of vaginal opening). The authors suggest that the onset of puberty in the female rat is brought about by a gradual increase in estrogen secretion which, acting at the CNS pituitary level, triggers a preovulatory proestrous like surge of gonadotropins and prolactin.",
author = "Sergio Ojeda and Wheaton, {J. E.} and Jameson, {H. E.} and McCann, {S. M.}",
year = "1976",
language = "English (US)",
volume = "98",
pages = "630--638",
journal = "Endocrinology",
issn = "0013-7227",
publisher = "The Endocrine Society",
number = "3",

}

TY - JOUR

T1 - The onset of puberty in the female rat

T2 - changes in plasma prolactin, gonadotropins, luteinizing hormone releasing hormone (LHRH), and hypothalamic LHRH content

AU - Ojeda, Sergio

AU - Wheaton, J. E.

AU - Jameson, H. E.

AU - McCann, S. M.

PY - 1976

Y1 - 1976

N2 - In order to study the sequence of hormonal changes that accompany the onset of puberty in the female rat, immature animals were sacrificed by decapitation between days 32 and 38, and plasma titers of gonadotropins, prolactin, and LHRH, and the hypothalamic content of LHRH were determined by specific radioimmunoassays (RIA). Animals were decapitated at 10:00 and 16:00 h throughout the pubertal period, the uterine weight was recorded, and the ovaries were inspected for signs of ovulation. Animals with the vagina closed were grouped according to the condition of the uterus as anestrus (A), early proestrus (EP) and late proestrus (LP), the uterus being unstimulated, dilated with some fluid, or ballooned, respectively. Vaginal opening was usually associated with ovulation and in most cases occurred at the end of the late proestrous phase. Animals were studied up to 3 days after vaginal opening and were grouped according to vaginal cytology. Uterine weight, taken as an index of estrogen secretion, was low during A, increased during EP, and reached a peak at LP, declining thereafter. Plasma LH and FSH were low from A until the afternoon of LP. At this time, uterine weight was maximal and both gonadotropins increased dramatically. The following morning (estrus), LH, but not FSH, had returned to basal values. FSH returned to basal levels on the afternoon of estrus. Plasma prolactin was low in the morning during the entire period, but showed peaks on the afternoons, which reached a maximum at LP and declined thereafter following the pattern of changes in uterine weight. Plasma LHRH was uniformly low throughout the entire pubertal period, whereas hypothalamic LHRH content declined on the morning of estrus (day of vaginal opening). The authors suggest that the onset of puberty in the female rat is brought about by a gradual increase in estrogen secretion which, acting at the CNS pituitary level, triggers a preovulatory proestrous like surge of gonadotropins and prolactin.

AB - In order to study the sequence of hormonal changes that accompany the onset of puberty in the female rat, immature animals were sacrificed by decapitation between days 32 and 38, and plasma titers of gonadotropins, prolactin, and LHRH, and the hypothalamic content of LHRH were determined by specific radioimmunoassays (RIA). Animals were decapitated at 10:00 and 16:00 h throughout the pubertal period, the uterine weight was recorded, and the ovaries were inspected for signs of ovulation. Animals with the vagina closed were grouped according to the condition of the uterus as anestrus (A), early proestrus (EP) and late proestrus (LP), the uterus being unstimulated, dilated with some fluid, or ballooned, respectively. Vaginal opening was usually associated with ovulation and in most cases occurred at the end of the late proestrous phase. Animals were studied up to 3 days after vaginal opening and were grouped according to vaginal cytology. Uterine weight, taken as an index of estrogen secretion, was low during A, increased during EP, and reached a peak at LP, declining thereafter. Plasma LH and FSH were low from A until the afternoon of LP. At this time, uterine weight was maximal and both gonadotropins increased dramatically. The following morning (estrus), LH, but not FSH, had returned to basal values. FSH returned to basal levels on the afternoon of estrus. Plasma prolactin was low in the morning during the entire period, but showed peaks on the afternoons, which reached a maximum at LP and declined thereafter following the pattern of changes in uterine weight. Plasma LHRH was uniformly low throughout the entire pubertal period, whereas hypothalamic LHRH content declined on the morning of estrus (day of vaginal opening). The authors suggest that the onset of puberty in the female rat is brought about by a gradual increase in estrogen secretion which, acting at the CNS pituitary level, triggers a preovulatory proestrous like surge of gonadotropins and prolactin.

UR - http://www.scopus.com/inward/record.url?scp=0017252311&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0017252311&partnerID=8YFLogxK

M3 - Article

VL - 98

SP - 630

EP - 638

JO - Endocrinology

JF - Endocrinology

SN - 0013-7227

IS - 3

ER -