The influence of long term estrogen treatment on plasma prolactin levels induced by ether anesthesia in ovariectomized rats

1977 ◽  
Vol 33 (4) ◽  
pp. 536-537 ◽  
Author(s):  
G. T. Goodman ◽  
D. M. Lawson
Keyword(s):  
Estrogen Treatment ◽  
Ovariectomized Rats ◽  
Plasma Prolactin ◽  
Ether Anesthesia

Development and amplification of mid-afternoon surges of prolactin secretion in ovariectomized immature rats

1986 ◽  
Vol 110 (2) ◽  
pp. 361-366 ◽  
Author(s):  
H. F. Urbanski ◽  
S. R. Ojeda
Keyword(s):  
Prolactin Secretion ◽  
Ovariectomized Rats ◽  
Female Rat ◽  
Plasma Prolactin ◽  
Short Term ◽  
Small Magnitude ◽  
Neuroendocrine Mechanisms ◽  
Phases Of Development ◽  
Juvenile Development

ABSTRACT The immature female rat shows a mid-afternoon surge of prolactin secretion which reaches a maximum on the day of first pro-oestrus. The present experiments were undertaken to elucidate the mechanisms which underly the development of this prolactin discharge. Detailed plasma prolactin profiles were obtained from short-term (48 h) ovariectomized rats at 23, 28 or 37 days of age. In the two older groups, but not the youngest, a mid-afternoon surge of prolactin secretion occurred in spite of the absence of the ovaries. To exclude the possibility that such an apparent ovarian-independent discharge of prolactin was due to an oestradiol effect which persisted for 2 days following ovariectomy, another study was conducted using long-term ovariectomized animals. Plasma profiles were obtained from neonatally ovariectomized rats at ages equivalent to juvenile (26–28 days), peripubertal (38–41 days) or adult (46–49 days) phases of development. A mid-afternoon surge of prolactin secretion was observed in the majority of animals (eight out of twelve) irrespective of the interval after ovariectomy; this finding further indicates that in the female rat there is a centrally originated mid-afternoon episode of prolactin secretion which is expressed during juvenile development even in the absence of the ovaries. The relatively small magnitude of these ovarian-independent prolactin discharges (c.f. the preovulatory prolactin surge) suggested that in the intact animal they are amplified by ovarian secretions. To test this hypothesis, oestradiol-containing silicone elastomer capsules were implanted s.c. into juvenile rats, immediately after ovariectomy, and plasma prolactin profiles examined 2 days later (28 days of age). In all cases the prolactin surge was greatly amplified and in many instances the magnitude was identical to that observed at first pro-oestrus. These data suggest that development of the large pro-oestrous surge of prolactin secretion involves the interplay of at least two distinct neuroendocrine mechanisms: (1) a centrally originated ovarian-independent signal and (2) an amplification effect exerted by ovarian oestradiol. J. Endocr. (1986) 110, 361–366

A new model for the induction of proestrus-like LH surges by estradiol in long-term ovariectomized rats

1985 ◽  
Vol 110 (1_Suppla) ◽  
pp. S11
Author(s):  
C. HIEMKE ◽  
A. SCHMID ◽  
R. GHRAF
Keyword(s):  
Ovariectomized Rats ◽  
New Model

Long-Term Effect of Haloperidol, Olanzapine, and Risperidone on Plasma Prolactin Levels in Patients With First-Episode Psychosis

2012 ◽  
Vol 32 (6) ◽  
pp. 804-808 ◽  
Author(s):  
Rocio Pérez-Iglesias ◽  
Ignacio Mata ◽  
Obdulia Martínez-García ◽  
M. Teresa Garcia-Unzueta ◽  
Jose Antonio Amado ◽  
...  
Keyword(s):  
First Episode Psychosis ◽  
Term Effect ◽  
First Episode ◽  
Plasma Prolactin ◽  
Long Term Effect ◽  
Episode Psychosis

Antioestrogen inhibition of oestradiol-induced alterations in hypothalamic noradrenaline turnover

1985 ◽  
Vol 106 (1) ◽  
pp. 37-42 ◽  
Author(s):  
C. Hiemke ◽  
B. Poetz ◽  
R. Ghraf
Keyword(s):  
Brain Area ◽  
Serum Levels ◽  
Ovariectomized Rats ◽  
Noradrenaline Turnover ◽  
Stimulatory Action ◽  
Enhanced Sensitivity ◽  
Oestradiol Benzoate ◽  
Lh Release ◽  
Secretory System

ABSTRACT Long-term (4–6 weeks) ovariectomized rats were injected with either oestradiol benzoate (OB; 20 μg s.c.) or monohydroxytamoxifen (MTAM; 0·2 mg i.p.) plus OB. Oestradiol benzoate was administered at 12.00 h on day 0 and MTAM was given immediately before OB, followed by further injections twice daily to maintain sufficiently high antioestrogen levels. When given alone, OB reduced the serum levels of LH during the morning (08.00–09.00 h) and afternoon (17.30–18.30 h) hours of day 3 after priming. The feedback actions of OB on LH release were accompanied by time-dependent alterations of noradrenaline turnover in the preoptic–anterior hypothalamic brain area (POAH). On day 3 after priming the noradrenaline turnover rate was reduced in the morning and increased in the afternoon. The increase correlated with an enhanced sensitivity of the LH secretory system to progesterone. The antioestrogen MTAM blocked the OB-induced sensitization of LH release to the stimulatory action of progesterone and interfered with the stimulatory long-term effect of oestradiol on hypothalamic noradrenaline turnover. The data strongly support the view that the oestrogen-induced afternoon increase of noradrenaline turnover in the POAH represents a pre-requisite for the induction of LH surges. The stimulatory effect of oestradiol on hypothalamic noradrenaline turnover seems to be mediated by a classical oestrogen receptor mechanism. J. Endocr. (1985) 106, 37–42

scholarly journals Changes in prolactin secretion in the short- and long-term after adrenalectomy

2012 ◽  
Vol 56 (4) ◽  
pp. 244-249 ◽  
Author(s):  
Maria Thereza C. Laguna-Abreu ◽  
Carla Germano ◽  
Ayrton C. Moreira ◽  
José Antunes-Rodrigues ◽  
Lucila Elias ◽  
...  
Keyword(s):  
Hpa Axis ◽  
Plasma Corticosterone ◽  
Prolactin Secretion ◽  
Plasma Prolactin ◽  
Peptidergic Neurons ◽  
Prolactin Release ◽  
Short And Long Term ◽  
Hypothalamus Pituitary Adrenal Axis ◽  
Pituitary Adrenal Axis

OBJECTIVE: To evaluate the modulation of the hypothalamus-pituitary-adrenal axis (HPA) on prolactin secretion in rats after adrenalectomy (ADX). MATERIALS AND METHODS: Plasma corticosterone, ACTH, and prolactin concentrations were measured by radioimmunoassay in rats after bilateral ADX in the short- (3 hours and 1day) and long-term (3, 7, and 14 days). RESULTS: Animals that underwent ADX showed undetectable corticosterone levels and a triphasic ACTH response with a transient increase (3h), a decrease (1d), and further increase in the long-term after ADX. Sham animals showed a marked increase in corticosterone and ACTH levels three hours after surgery, with a decrease to basal levels thereafter. Plasma prolactin levels were not changed after ADX. CONCLUSION: There are different points of equilibrium in the HPA axis after the glucocorticoid negative feedback is removed. Prolactin plasma secretion is not altered in the short or long- term after ADX, suggesting that the peptidergic neurons essential for prolactin release are not activated after ADX.

scholarly journals Effect of estrogen treatment on plasma oxytocin and vasopressin in ovariectomized rats.

1979 ◽  
Vol 26 (2) ◽  
pp. 197-205 ◽  
Author(s):  
KEN'ICHI YAMAGUCHI ◽  
TAKAO AKAISHI ◽  
HIDEO NEGORO
Keyword(s):  
Estrogen Treatment ◽  
Ovariectomized Rats
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