Changes in the Weight of the Adrenal Glands and in the Concentration of Plasma Corticosterone in Perinatal Rats After Prenatal Treatment With Oestradiol Benzoate

Eguchi, Yawara; Arishima, Kazuyoshi; Morikawa, Yoshio; Hashimoto, Yoshiyuki

doi:10.1677/joe.0.0690427

Cited by 10 publications

(5 citation statements)

References 11 publications

(10 reference statements)

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“…That the adrenal glands of the newborn rat are activated at birth is suggested by the high levels of circulating corticosterone and the sub sequent decrease until 8 h. Our results are in good agreement with those of Eguchi et al (11), who found that the plasma corticosterone concentration increased during delivery of rat fetuses, reaching a maximum about 2 h after birth and then decreasing gradually until 12 h.…”

Section: Plasma Corticosteronesupporting

confidence: 93%

“…A slight increase during the last hours of in trauterine life is followed by a rapid decrease between hours 2 and 4. These results are con sistent with previous data on the decrease of adrenal weight between birth and the first 2 days of life (4,7,11). The adrenals have a hyperhemic appearance at birth whichdisappears by 4 h, suggesting that the glands were strongly stimulated.…”

Section: Adrenal Weightsupporting

confidence: 91%

“…The administra tion of ACTH to an anencephalic newborn hu man prevented regression of the fetal zone (21), whereas HCG or estrogen administration did not prevent this regression. It has recently been shown, however, that estradiol benzoate in jections to 20-day-old rat fetuses prevented the neonatal decrease of both adrenal weight and adrenalcortex cell size (11). Under these con ditions, the disappearance of maternal or placental sex hormones in the newborn rat could influence the postnatal involution of the adrenals, since it is known that estrogens stimulate pituitary ACTH secretion in the adult rat (6).…”

Section: Adrenal Weightmentioning

confidence: 99%

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Increased Adrenocortical Activity in the Newborn Rat

Corbier¹,

Roffi²

1978

Neonatology

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The evolution of adrenal weight, of the level of ascorbic acid and the levels of adrenal and plasma corticosterone were measured in the newborn rat at the moment of birth and during the hours that followed. Between 0 and 4 h, the absolute and relative weights of the adrenals decreased by 14 and 10%, respectively, and were even lower at 24 h. The amount of ascorbic acid in the adrenals decreases by 17% between 0 and 4 hours. Adrenal corticosterone levels dropped abruptly during the first hour of life, accompanied by an increase in the plasma levels of this hormone. These results suggest that during the initial hours of life, there is a significant stimulation of the adrenal cortex, probably connected to birth-related stress phenomena. An encephalectomy, leaving the pituitary in situ, or decapitation of the rat fetus during the last days of gestation impair the growth and endocrine activity of the adrenal glands. Normal adrenocortical function is restored by injecting hypothalamic extracts or ACTH at the time of surgery (9, 16). At the end of the gestation period, rat fetuses respond to such stimuli as epinephrine or formalin injection by depleting adrenal ascorbic acid levels 1 h after the stress (5, 24). The administration of ether, or laparotomy plus ether, on day 20 of gestation induce an immediate rise of fetal hypothalamic CRF and adrenal corticosterone (12, 27). All these results afford good evidence for an autonomous hypothalamic-hypophyseal-adrenocortical axis during the last days of gestation of the rat fetus. The purpose of the present report was to discover if the adrenal cortex was activated by the stress of labor and birth, as well as by adaptation of the newborn animal to new environmental conditions. The parameters examined were adrenal weight, the levels of adrenal ascorbic acid and corticosterone and the circulating corticosterone levels during the hours following birth.

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Section: Plasma Corticosteronesupporting

confidence: 93%

Section: Adrenal Weightsupporting

confidence: 91%

Section: Adrenal Weightmentioning

confidence: 99%

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Increased Adrenocortical Activity in the Newborn Rat

Corbier¹,

Roffi²

1978

Neonatology

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“…(Josimovich et al, 1954;Cohen, 1959;Eguchi and Ariyuki, 1963). This reduction is not absolutely due to the absence of maternal ACTH (see review by Eguchi, 1969), but seemingly due to a blockade of the newborn pituitary by a markedly high level of plasma corticosterone which occurs at and just after delivery (Eguchi et al, 1976). Estradiol benzoate, when given prenatally, prevents both an extreme increase in the concentration of plasma corticosterone at and just after birth and a decline of the weight of neonatal adrenals (Eguchi et al, 1976).…”

mentioning

confidence: 99%

Failure of estradiol benzoate given after birth to prevent the adrenal glands from shrinking in newborn rats.

et al. 1976

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SynopsisTwo hr after birth, newborn rats were given a subcutaneous injection of 0.01mg estradiol benzoate dissolved in 0.05ml sesame oil. Other siblings were given sesame oil alone. Autopsy was performed on days 1, 2 and 3 after birth. Gravimetric and histologic examinations of the adrenals from these animals and from normal littermate controls were made together with the determination of plasma corticosterone concentrations.In all the three groups of rats, estrogen-treated, oil-treated and nontreated, the weight of the adrenal glands declined with a concomitant decrease in the plasma corticosterone concentrations.The results indicate that estradiol benzoate, when given after birth, does not prevent the neonatal adrenal from shrinking.

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“…or to the hypothalamic CRF mobilized by the METimposed reduction of corticosterone levels in circulation. Similarly, Eguchi et al [6] have suggested that the pituitary is very sensitive to circulating corticosteroids in perinatal life. The results obtained in the present study may, at least partly, be ascribed to the slower degradation and inactivation of MET in 5-than in 10-day-old rats.…”

Section: Discussionmentioning

confidence: 87%

Pituitary and Adrenal Glands in Neonatal Rats Studied by Metopirone (Su4885)

Milković¹,

Peruzović²,

Paunović³

1982

Neonatology

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One half of each litter of the 2- and 7-day-old rats was injected twice daily for 3 consecutive days with 15 mg/l00gbody weight of metopirone (MET) in 0.05 ml of saline, and the remaining littermates with saline only. At the ages of 5 and 10 days, one half of the pups was sacrificed immediately, and the second half 20 min after s.c. injection of histamine as a stressor. MET depressed body weight and induced adrenal hypertrophy in the 5- and 10-day-old rats, and pituitary hypertrophy in the 5-day-old rats only. In resting condition the adrenal glands of the 5-day-old rats treated with MET contained less corticosterone (determined fluorometrically) than the 5-day-old control and the 10-day-old pups treated also with MET. Furthermore, neonatal MET treatment induced (histamine) stress response by the increase in adrenal corticosterone content in the 10-day-old rats, and by the increase in corticosterone content in plasma in both ages. The results indicate high sensitivity of the young neonatal rats to hormonal manipulations. They also yield additional support to the concept of functional integrity of the hypothalamo-pituitary-adrenocortical system in neonatal rats, and to the flexibility of the postnatal developmental pattern of stress response.

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Changes in the Weight of the Adrenal Glands and in the Concentration of Plasma Corticosterone in Perinatal Rats After Prenatal Treatment With Oestradiol Benzoate

Cited by 10 publications

References 11 publications

Increased Adrenocortical Activity in the Newborn Rat

Increased Adrenocortical Activity in the Newborn Rat

Failure of estradiol benzoate given after birth to prevent the adrenal glands from shrinking in newborn rats.

Pituitary and Adrenal Glands in Neonatal Rats Studied by Metopirone (Su4885)

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