IN VITRO UPTAKE OF TRITIATED OESTRADIOL BY THE RAT ANTERIOR HYPOTHALAMUS DURING THE OESTROUS CYCLE

1970 ◽  
Vol 63 (4) ◽  
pp. 577-584 ◽  
Author(s):  
Junzo Kato
Keyword(s):  
Posterior Hypothalamus ◽  
Anterior Hypothalamus ◽  
Oestrous Cycle ◽  
Physiological Regulation ◽  
Cortex Cerebri ◽  
Anterior Hypophysis ◽  
Cyclic Changes ◽  
In Vitro Uptake

ABSTRACT The anterior, middle and posterior hypothalamus, the cortex cerebri, the anterior hypophysis, and the diaphragm of postpubertal rats at different phases of the oestrous cycle were incubated in vitro with tritiated 17β-oestradiol. Uptake of radioactivity by the anterior hypothalamus at prooestrus and oestrus was lower than that at dioestrus. In contrast no fluctuation in the concentration of the radioactivity in the other parts of brain, the hypophysis and muscle was observed during the oestrous cycle. These in vitro findings are consistent with the in vivo observations of cyclic changes in phase with the oestrous cycle of the amount of radioactive oestradiol taken up by the anterior hypothalamus following the injection of tritiated oestradiol (Kato et al. 1969b). Thus it is further suggested that the oestradiol receptor in the anterior hypothalamus of the rat is involved in the physiological regulation and maintenance of cyclic changes in the hypothalamo-pituitary system through the mechanism of action of feedback of oestrogen.

IN VITRO UPTAKE OF TRITIATED OESTRADIOL BY THE ANTERIOR HYPOTHALAMUS AND HYPOPHYSIS OF THE RAT

1970 ◽  
Vol 64 (4) ◽  
pp. 687-695 ◽  
Author(s):  
Junzo Kato
Keyword(s):  
Incubation Medium ◽  
Posterior Hypothalamus ◽  
Anterior Hypothalamus ◽  
Ovariectomized Rats ◽  
Free Medium ◽  
Cortex Cerebri ◽  
Anterior Hypophysis ◽  
In Vitro Uptake

ABSTRACT The anterior, middle, and posterior hypothalamus, the cortex cerebri, the anterior hypophysis as well as the diaphragm of adult ovariectomized rats were incubated in vitro with tritiated 17β-oestradiol. The uptake of tritiated oestradiol was differentially distributed intracerebrally with higher accumulation in the anterior hypothalamus and the hypophysis. Lowering the temperature of the incubation medium caused a reduction in the uptake of radioactivity by the anterior hypothalamus as compared to that found in other brain tissues. Tritiated oestradiol taken up in vitro by the anterior hypothalamus and the hypophysis tended to be retained after further incubation in a steroid-free medium. The addition of non-radioactive 17β-oestradiol to the medium inhibited the uptake of tritiated oestradiol by these tissues. Moreover, pretreatment with non-radioactive 17β-oestradiol in vivo prevented the preferential accumulation of tritiated oestradiol in vitro in the anterior hypothalamus and the hypophysis. These results indicate that oestradiol is preferentially taken up in vitro by the anterior hypothalamus and the hypophysis of the rat.

Changes in the hypothalamic contents of LHRH-I and -II and in pituitary responsiveness to synthetic chicken LHRH-I and -II during the progesterone-induced surge of LH in the laying hen

1990 ◽  
Vol 127 (3) ◽  
pp. 487-496 ◽  
Author(s):  
S. C. Wilson ◽  
R. A. Chairil ◽  
F. J. Cunningham ◽  
R. T. Gladwell
Keyword(s):  
Plasma Concentration ◽  
Pituitary Gland ◽  
Laying Hens ◽  
Plasma Concentrations ◽  
Posterior Hypothalamus ◽  
Anterior Hypothalamus ◽  
Significant Fall ◽  
Basal Plasma

ABSTRACT The contents of LHRH-I and -II in the anterior hypothalamus and posterior hypothalamus (including the mediobasal hypothalamus and median eminence) were measured at 90, 180 and 360 min after the i.m. injection of laying hens with progesterone. Whilst no changes were observed in the content of LHRH-I in the anterior hypothalamus, LHRH-I in the posterior hypothalamus tended to fall at 90 and 180 min after injection of progesterone in hens maintained on 16 h light:8 h darkness (16L:8D) and 8L:16D respectively. Pretreatment of laying hens with tamoxifen significantly increased the hypothalamic contents of LHRH-I and -II, raised the basal plasma concentration of LH and modified the LH response to progesterone injection. In hens in which tamoxifen prevented an increase in the plasma concentration of LH after progesterone injection, the content of LHRH-I in the posterior hypothalamus remained unchanged. In contrast, in hens in which progesterone stimulated a steep increase in LH within 90 min, there was a pronounced and significant fall in LHRH-I content of the posterior hypothalamus. No change in the hypothalamic content of LHRH-II was observed during the progesterone-induced surge of LH until plasma concentrations had attained maximal values or started to decline. Then, in hens maintained on 16L:8D, a significant fall in the content of LHRH-II in the anterior hypothalamus was found at both 180 and 360 min after injection with progesterone. Tests in vitro and in vivo of the responsiveness of the pituitary gland to synthetic LHRH-I and -II revealed no change at 90 min after injection of laying hens with progesterone, when plasma concentrations of LH were increasing, but a pronounced reduction when plasma LH concentrations were maximal or falling. These results suggest that LHRH-I mediates in the progesterone-induced increase in the plasma concentration of LH. Although the subsequent decline in plasma LH was associated with a reduced responsiveness of the pituitary gland to LHRH, a significant correlation between the contents of LHRH-I and -II in the anterior hypothalamus and a fall in the hypothalamic content of LHRH-II when plasma LH was maximal or declining allows the possibility of an involvement of this peptide in the neuroendocrine events preceding ovulation. Journal of Endocrinology (1990) 127, 487–496

THE MECHANISM OF OESTRADIOL BINDING IN RAT HYPOTHALAMUS: EFFECT OF ANDROGENIZATION

1971 ◽  
Vol 51 (2) ◽  
pp. 271-282 ◽  
Author(s):  
MARIETTA VÉRTES ◽  
R. J. B. KING
Keyword(s):  
Anterior Pituitary ◽  
Specific Binding ◽  
Later Life ◽  
Posterior Hypothalamus ◽  
Anterior Hypothalamus ◽  
In Vitro System ◽  
Order Of Magnitude ◽  
Cell Fractions

SUMMARY The uptake of [6,7-3H]oestradiol in vivo and in vitro by cell fractions from regions of rat brain and the anterior pituitary gland has been studied. Cytoplasmic and nuclear receptors were detected in anterior and posterior hypothalamus but not in brain cortex. After labelling in vivo, tissues took up [6,7-3H]oestradiol in the following order of magnitude: anterior pituitary > anterior hypothalamus > posterior hypothalamus > cortex. With the exception of the cortex, all extracts from mature tissues had a higher uptake/mg protein than did extracts from immature animals. In the in-vitro system, oestradiol-17β competed with [6,7-3H]oestradiol-17β in the hypothalamus whereas progesterone, testosterone and oestradiol-17α did not. In the pituitary, oestradiol-17α and 17β competed for binding sites. A single injection of testosterone propionate on the second day of life affected [6,7-3H]oestradiol binding in later life. By 28 days of age, the androgenized animals had a lower nuclear and higher cytoplasmic uptake of [6,7-3H]oestradiol in anterior hypothalamus. This effect was not seen in the posterior hypothalamus or cortex. Binding was decreased in all fractions from the pituitary. In mature animals (60 days old), binding fell in both nuclear and cytoplasmic fractions from anterior hypothalamus and pituitary. The nuclei from posterior hypothalamus also took up less [6,7-3H]oestradiol after androgenization. Androgenization affected specific binding in uteri at both 28 and 60 days of age.

RNA SYNTHESIS IN THE RAT ANTERIOR HYPOTHALAMUS AND PITUITARY: RELATION TO NEONATAL ANDROGEN AND THE OESTROUS CYCLE

1970 ◽  
Vol 48 (1) ◽  
pp. 125-137 ◽  
Author(s):  
D. F. SALAMAN
Keyword(s):  
Ribosomal Rna ◽  
Anterior Pituitary ◽  
Rna Synthesis ◽  
Specific Activity ◽  
Gradient Centrifugation ◽  
Anterior Hypothalamus ◽  
Oestrous Cycle ◽  
Uridine Incorporation ◽  
Cyclic Changes

SUMMARY RNA from the anterior hypothalamus and anterior pituitary of rats has been labelled by incubation in vitro with [3H]uridine and characterized by density gradient centrifugation. A study of normal females during the oestrous cycle showed cyclic changes in [3H]uridine incorporation into rapidly labelled RNA (rl-RNA) both in the anterior pituitary and hypothalamus. In both tissues the specific activity of RNA was low at dioestrus and high at oestrus and metoestrus. In androgenized females, incorporation into hypothalamic rl-RNA was less than the oestrus—metoestrus level and similar to that at dioestrus, while incorporation into anterior pituitary rl-RNA was similar to the oestrus—metoestrus level and greater than at dioestrus. [3H]Uridine incorporation into ribosomal RNA (r-RNA) of anterior hypothalamus and pituitary was also demonstrated by incubation for 4 h. Under these conditions there was no effect of androgenization on hypothalamic r-RNA, but the specific activity of pituitary r-RNA was greater than normal.

VARIABLE UPTAKE OF TRITIATED OESTRADIOL BY THE ANTERIOR HYPOTHALAMUS IN THE POSTPUBERTAL FEMALE RAT

1969 ◽  
Vol 61 (4) ◽  
pp. 585-591 ◽  
Author(s):  
Junzo Kato ◽  
Machiko Inaba ◽  
Takashi Kobayashi
Keyword(s):  
Mechanism Of Action ◽  
Anterior Hypothalamus ◽  
Oestrous Cycle ◽  
The Other ◽  
Female Rat ◽  
Physiological Regulation ◽  
Physiological Dose ◽  
Cyclic Changes

ABSTRACT Cyclic changes in phase with the oestrous cycle with regard to the amount of radioactive oestradiol taken up by the anterior hypothalamus were found in postpubertal rats following the injection of a physiological dose of tritiated oestradiol. Uptake at prooestrus was lower than that at dioestrus. In contrast no fluctuations in the concentration of the radioactivity in the other parts of brain, the hypophysis, and muscle or plasma were observed throughout the oestrous cycle. These findings suggest that the oestradiol receptor in the anterior hypothalamus of the rat is involved in the physiological regulation and maintenance of cyclical changes of the hypothalamo-pituitary system through the mechanism of action of feedback of oestrogen.

scholarly journals Intracellular relationships of the oestrogen receptor in the rat uterus and hypothalamus during the oestrous cycle

1978 ◽  
Vol 172 (1) ◽  
pp. 37-47 ◽  
Author(s):  
J O White ◽  
S Thrower ◽  
L Lim
Keyword(s):  
Oestrogen Receptor ◽  
Oestrous Cycle ◽  
Female Rats ◽  
Nuclear Binding ◽  
Age Related ◽  
Wet Weight ◽  
Cyclic Changes ◽  
Nuclear Content

Simultaneous measurements were made of the specific oestrogen receptor in the nuclear and cytosol fractions prepared from the uterus and hypothalamus of 50–81-day-old female rats undergoing a 4-day oestrous cycle. In the uterus, the content of nuclear receptor fluctuated in concert with known cyclic changes in the secretion of oestrogen, being maximal at pro-oestrus. Over the period of 50–81 days, the nuclear content at all phases increased with age, again corresponding to known age-related increases in ovarian secretion of oestrogen. This age-related increase in nuclear content, averaged from the values of the different phases in each age group, was related to equivalent increases in uterine wet weight, an increase of 1 pmol of receptor being accompanied by an increase of 80–90 mg. The concentration of cytosol receptor was maintained constant, with respect to wet weight, throughout the cycle and with age, irrespective of changes in nuclear content. In the uterus of normal mature females, translocation of receptor into the nucleus did not lead to depletion of cytosol receptor, suggesting a process of continuous replenishment/synthesis. In the hypothalamus, the nuclear content of oestrogen receptor was also maximal at pro-oestrus. In contrast with the uterus, the content of hypothalamic cytosol receptor was minimal at this phase and reflects depletion of the cytosol receptor, possibly as a result of translocation. The extent of translocation was low compared with that in the uterus and did not alter with age during the age-period studied. This low nuclear binding of the receptor in vivo is discussed in relation to the presence of a cytosol factor, present in limiting amounts, which in vitro mediates the binding of cytosol receptor to oligo(dT)-cellulose. The difference in the physiological response of the uterus and of the hypothalamus to oestrogens may be related to the extent of nuclear binding of receptor.

In Vivo and in Vitro Uptake of Boronated Compounds by B16-BL6 Murine Melanoma

1993 ◽  
pp. 619-622
Author(s):  
C. A. Elstad ◽  
K. R. Meinkoth ◽  
B. A. Mathison ◽  
G. G. Meadows ◽  
D. H. Kinder ◽  
...  
Keyword(s):  
Murine Melanoma ◽  
In Vitro Uptake

Radioreceptor and biological characterization of cholecystokinin and gastrin in the chicken

1984 ◽  
Vol 246 (3) ◽  
pp. G296-G304
Author(s):  
S. R. Vigna
Keyword(s):  
Acid Secretion ◽  
Gastric Acid Secretion ◽  
Gastric Acid ◽  
Amylase Secretion ◽  
Physiological Regulation ◽  
Chicken Brain ◽  
Specific Radioimmunoassay ◽  
Cck Receptor Antagonist

Radioimmunoassay, radioreceptor assays, and bioassays were used to demonstrate that chicken brain and antrum extracts contain cholecystokinin (CCK)-like and gastrinlike peptides, respectively. C-terminal-specific radioimmunoassay of partially purified chicken CCK and gastrin gave dilution curves parallel to those of the mammalian peptides. Mouse cerebral cortical and rat pancreatic membrane radioreceptor assays were used to differentiate CCK- from gastrinlike peptides on the basis of the different CCK versus gastrin specificities of the two receptors. Confirmation of the biological activity of chicken brain CCK was obtained by stimulation of amylase secretion from rat pancreatic lobules in vitro. The specificity of this response was demonstrated by the inhibition of chicken CCK-stimulated amylase secretion by the specific CCK receptor antagonist dibutyryl cGMP. Chicken antral gastrin stimulated gastric acid secretion from the rat stomach in vivo. In contrast to previous hypotheses, it is proposed that chickens have significant amounts of an antral gastrinlike peptide and that therefore it is possible that gastrin is involved in the physiological regulation of gastric acid secretion in chickens.

In vitro-produced horse embryos exhibit a very narrow window of acceptable recipient mare uterine synchrony compared with in vivo-derived embryos

2019 ◽  
Vol 31 (12) ◽  
pp. 1904 ◽  
Author(s):  
Juan Cuervo-Arango ◽  
Anthony N. Claes ◽  
Tom A. E. Stout
Keyword(s):  
Pregnancy Rate ◽  
Pregnancy Loss ◽  
Oestrous Cycle ◽  
Ongoing Pregnancy ◽  
Ongoing Pregnancy Rate ◽  
Wide Range ◽  
In Pregnancy

In recent years, the number of equine invitro-produced embryos (IVP) has increased markedly; as yet, there are few reports on what constitutes an ‘ideal’ recipient for an IVP embryo. This study retrospectively investigated the effects of recipient mare oestrous cycle characteristics on the likelihood of pregnancy after transfer of IVP (n=264) and invivo-derived embryos (n=262). IVP embryos tolerated only a narrow window of recipient mare ‘synchrony’, with transfer on Day 4 after ovulation resulting in a higher likelihood of ongoing pregnancy (69%) than transfer on Days 3, 5 or 6 (53.2%, 41.3% and 23.1% respectively; P=0.02). In contrast, Day 8 invivo-derived embryos tolerated a wide range of uterine (a)synchrony, with no difference in pregnancy or pregnancy loss for recipients that ovulated between Day 4 and Day 9 before transfer. However, transferring invivo-derived embryos to recipients that had a longer oestrus preceding transfer resulted in higher Day 12 and ongoing pregnancy rate (P<0.01). This effect was not significant in IVP embryos. In conclusion, Day 6–8 IVP blastocysts survive best after transfer to Day 4 recipient mares; Day 8 invivo-derived embryos survive equally well in Day 4–9 recipients, but do better in mares that have a long preceding oestrus.

Analysis of STAT1 expression and biological activity reveals interferon-tau-dependent STAT1-regulated SOCS genes in the bovine endometrium

2016 ◽  
Vol 28 (4) ◽  
pp. 459 ◽  
Author(s):  
A. Vitorino Carvalho ◽  
C. Eozenou ◽  
G. D. Healey ◽  
N. Forde ◽  
P. Reinaud ◽  
...  
Keyword(s):  
Biological Activity ◽  
Nuclear Translocation ◽  
Differentially Expressed Gene ◽  
Oestrous Cycle ◽  
Cytokine Signaling ◽  
Gene Promoters ◽  
Interferon Tau ◽  
Endometrial Cells

Signal transducer and activator of transcription (STAT) proteins are critical for the regulation of numerous biological processes. In cattle, microarray analyses identified STAT1 as a differentially expressed gene in the endometrium during the peri-implantation period. To gain new insights about STAT1 during the oestrous cycle and early pregnancy, we investigated STAT1 transcript and protein expression, as well as its biological activity in bovine tissue and cells of endometrial origin. Pregnancy increased STAT1 expression on Day 16, and protein and phosphorylation levels on Day 20. In cyclic and pregnant females, STAT1 was located in endometrial cells but not in the luminal epithelium at Day 20 of pregnancy. The expression of STAT1 during the oestrous cycle was not affected by progesterone supplementation. In vivo and in vitro, interferon-tau (IFNT) stimulated STAT1 mRNA expression, protein tyrosine phosphorylation and nuclear translocation. Using chromatin immunoprecipitation in IFNT-stimulated endometrial cells, we demonstrated an increase of STAT1 binding on interferon regulatory factor 1 (IRF1), cytokine-inducible SH2-containing protein (CISH), suppressor of cytokine signaling 1 and 3 (SOCS1, SOCS3) gene promoters consistent with the induction of their transcripts. Our data provide novel molecular insights into the biological functions of STAT1 in the various cells composing the endometrium during maternal pregnancy recognition and implantation.

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