Effects of 4-hydroxyandrostenedione and exogenous testosterone on blood concentrations of oestradiol and oviducal embryo transport in the rat

M. L. Forcelledo, H. B. Croxatto

Resultado de la investigación: Article

11 Citas (Scopus)

Resumen

The effect of decreasing oestrogen secretion on the oviducal migration of embryos was investigated in pregnant rats. The reduction of oestradiol production was achieved by administration of the aromatase inhibitor 4-hydroxy-4-androstene-3,17-dione (4-OH-A) at various times after coitus. When 4-OH-A was administered from days 2 to 5, nearly half the embryos were retained in the oviducts at midday on day 5 of pregnancy, in contrast with control animals in which all embryos were transferred to the uterus. Shorter treatments were less effective. The rate of secretion of oestradiol from the ovary on days 2-5 of pregnancy in control rats was low in the morning and high in the afternoon. Treatment with 4-OH-A from days 2 to 5 reduced the secretory surges of oestradiol in the afternoon by 77% without significantly changing the progesterone output. Systemic testosterone levels were significantly increased by this treatment. To assess whether changes in the transport of ova were due to an increase in testosterone concentrations the influence of exogenous testosterone on embryo transport and oestradiol production was tested. Testosterone administered by subdermal implants from days 2 or 3 to day 5 disturbed embryo transport in a manner similar to that of 4-OH-A. The longest period of testosterone administration decreased ovarian oestradiol production by 82% without changing the secretion of progesterone. Since ovarian oestradiol production in pregnant rats was reduced similarly by treatment with 4-OH-A and testosterone implants, and since exogenous oestradiol given s.c. on days 2, 3 and 4 counteracted the blocking effect of 4-OH-A and testosterone on embryo transport, the delay in oviducal transport of the embryos can be accounted for by decreased availability of oestradiol rather than increased testosterone production. This interpretation supports a crucial role for endogenous oestradiol in timing the passage of embryos to the uterus in the pregnant rat.

Idioma originalEnglish
Páginas (desde-hasta)93-100
Número de páginas8
PublicaciónJournal of Endocrinology
Volumen118
N.º1
EstadoPublished - 1988

Huella dactilar

Testosterone
Estradiol
Embryonic Structures
Uterus
Progesterone
Ovum Transport
formestane
Pregnancy
Aromatase Inhibitors
Oviducts
Coitus
hydroxide ion
Ovary
Estrogens

ASJC Scopus subject areas

  • Endocrinology
  • Endocrinology, Diabetes and Metabolism

Citar esto

@article{0c8697792581469997475e7bfa1d408c,
title = "Effects of 4-hydroxyandrostenedione and exogenous testosterone on blood concentrations of oestradiol and oviducal embryo transport in the rat",
abstract = "The effect of decreasing oestrogen secretion on the oviducal migration of embryos was investigated in pregnant rats. The reduction of oestradiol production was achieved by administration of the aromatase inhibitor 4-hydroxy-4-androstene-3,17-dione (4-OH-A) at various times after coitus. When 4-OH-A was administered from days 2 to 5, nearly half the embryos were retained in the oviducts at midday on day 5 of pregnancy, in contrast with control animals in which all embryos were transferred to the uterus. Shorter treatments were less effective. The rate of secretion of oestradiol from the ovary on days 2-5 of pregnancy in control rats was low in the morning and high in the afternoon. Treatment with 4-OH-A from days 2 to 5 reduced the secretory surges of oestradiol in the afternoon by 77{\%} without significantly changing the progesterone output. Systemic testosterone levels were significantly increased by this treatment. To assess whether changes in the transport of ova were due to an increase in testosterone concentrations the influence of exogenous testosterone on embryo transport and oestradiol production was tested. Testosterone administered by subdermal implants from days 2 or 3 to day 5 disturbed embryo transport in a manner similar to that of 4-OH-A. The longest period of testosterone administration decreased ovarian oestradiol production by 82{\%} without changing the secretion of progesterone. Since ovarian oestradiol production in pregnant rats was reduced similarly by treatment with 4-OH-A and testosterone implants, and since exogenous oestradiol given s.c. on days 2, 3 and 4 counteracted the blocking effect of 4-OH-A and testosterone on embryo transport, the delay in oviducal transport of the embryos can be accounted for by decreased availability of oestradiol rather than increased testosterone production. This interpretation supports a crucial role for endogenous oestradiol in timing the passage of embryos to the uterus in the pregnant rat.",
author = "Forcelledo, {M. L.} and Croxatto, {H. B.}",
year = "1988",
language = "English",
volume = "118",
pages = "93--100",
journal = "Journal of Endocrinology",
issn = "0022-0795",
publisher = "Society for Endocrinology",
number = "1",

}

TY - JOUR

T1 - Effects of 4-hydroxyandrostenedione and exogenous testosterone on blood concentrations of oestradiol and oviducal embryo transport in the rat

AU - Forcelledo, M. L.

AU - Croxatto, H. B.

PY - 1988

Y1 - 1988

N2 - The effect of decreasing oestrogen secretion on the oviducal migration of embryos was investigated in pregnant rats. The reduction of oestradiol production was achieved by administration of the aromatase inhibitor 4-hydroxy-4-androstene-3,17-dione (4-OH-A) at various times after coitus. When 4-OH-A was administered from days 2 to 5, nearly half the embryos were retained in the oviducts at midday on day 5 of pregnancy, in contrast with control animals in which all embryos were transferred to the uterus. Shorter treatments were less effective. The rate of secretion of oestradiol from the ovary on days 2-5 of pregnancy in control rats was low in the morning and high in the afternoon. Treatment with 4-OH-A from days 2 to 5 reduced the secretory surges of oestradiol in the afternoon by 77% without significantly changing the progesterone output. Systemic testosterone levels were significantly increased by this treatment. To assess whether changes in the transport of ova were due to an increase in testosterone concentrations the influence of exogenous testosterone on embryo transport and oestradiol production was tested. Testosterone administered by subdermal implants from days 2 or 3 to day 5 disturbed embryo transport in a manner similar to that of 4-OH-A. The longest period of testosterone administration decreased ovarian oestradiol production by 82% without changing the secretion of progesterone. Since ovarian oestradiol production in pregnant rats was reduced similarly by treatment with 4-OH-A and testosterone implants, and since exogenous oestradiol given s.c. on days 2, 3 and 4 counteracted the blocking effect of 4-OH-A and testosterone on embryo transport, the delay in oviducal transport of the embryos can be accounted for by decreased availability of oestradiol rather than increased testosterone production. This interpretation supports a crucial role for endogenous oestradiol in timing the passage of embryos to the uterus in the pregnant rat.

AB - The effect of decreasing oestrogen secretion on the oviducal migration of embryos was investigated in pregnant rats. The reduction of oestradiol production was achieved by administration of the aromatase inhibitor 4-hydroxy-4-androstene-3,17-dione (4-OH-A) at various times after coitus. When 4-OH-A was administered from days 2 to 5, nearly half the embryos were retained in the oviducts at midday on day 5 of pregnancy, in contrast with control animals in which all embryos were transferred to the uterus. Shorter treatments were less effective. The rate of secretion of oestradiol from the ovary on days 2-5 of pregnancy in control rats was low in the morning and high in the afternoon. Treatment with 4-OH-A from days 2 to 5 reduced the secretory surges of oestradiol in the afternoon by 77% without significantly changing the progesterone output. Systemic testosterone levels were significantly increased by this treatment. To assess whether changes in the transport of ova were due to an increase in testosterone concentrations the influence of exogenous testosterone on embryo transport and oestradiol production was tested. Testosterone administered by subdermal implants from days 2 or 3 to day 5 disturbed embryo transport in a manner similar to that of 4-OH-A. The longest period of testosterone administration decreased ovarian oestradiol production by 82% without changing the secretion of progesterone. Since ovarian oestradiol production in pregnant rats was reduced similarly by treatment with 4-OH-A and testosterone implants, and since exogenous oestradiol given s.c. on days 2, 3 and 4 counteracted the blocking effect of 4-OH-A and testosterone on embryo transport, the delay in oviducal transport of the embryos can be accounted for by decreased availability of oestradiol rather than increased testosterone production. This interpretation supports a crucial role for endogenous oestradiol in timing the passage of embryos to the uterus in the pregnant rat.

UR - http://www.scopus.com/inward/record.url?scp=0023880389&partnerID=8YFLogxK

M3 - Article

VL - 118

SP - 93

EP - 100

JO - Journal of Endocrinology

JF - Journal of Endocrinology

SN - 0022-0795

IS - 1

ER -