Binding Sites for Interleukin-6 in the Anterior Pituitary Gland

1992 ◽  
Vol 55 (2) ◽  
pp. 199-203 ◽  
Author(s):  
Masahide Ohmichi ◽  
Kenji Hirota ◽  
Koji Koike ◽  
Hirohisa Kurachi ◽  
Shirou Ohtsuka ◽  
...  
1987 ◽  
Vol 45 (6) ◽  
pp. 492-497 ◽  
Author(s):  
Michel Grino ◽  
Viviane Guillaume ◽  
Elias Castanas ◽  
Françoise Boudouresque ◽  
Bernard Conte-Devolx ◽  
...  

1979 ◽  
Vol 81 (1) ◽  
pp. 75-81 ◽  
Author(s):  
B. D. GREENSTEIN

Available high-affinity binding sites for 5α-dihydrotestosterone (DHT) were measured in cytosols obtained from the amygdala, hypothalamus, anterior pituitary gland and ventral prostate gland of 12-week-old rats at various times after orchidectomy, and in the corresponding tissues of 18-month-old male rats. It is suggested that the lower affinity of the DHT binding reaction in brain and ventral prostatic cytosols after orchidectomy or ageing respectively, may explain, at least in part, the changes in the responsiveness of the tissues to androgens.


1978 ◽  
Vol 76 (2) ◽  
pp. 211-218 ◽  
Author(s):  
K. K. SEN ◽  
K. M. J. MENON

Specific oestradiol binding to a receptor in nuclear and cytosol fractions of the rat anterior pituitary gland and pituitary responsiveness to gonadotrophin releasing hormone (GnRH) during the oestrous cycle have been studied. To accomplish this, both unoccupied and occupied oestradiol-binding sites in the cytosol and oestradiol-binding sites in the nucleus and total cell were measured during the oestrous cycle. The concentration of unoccupied and occupied sites and total oestradiol binding in the cytosol fluctuated during the cycle. At pro-oestrus, the concentration of cytosol receptor was diminished by about 40% and replenishment occurred during oestrus. On the other hand, a profound increase in concentrations of cellular and nuclear receptors occurred at pro-oestrus. Administration of GnRH significantly stimulated LH release at all stages of the cycle. The maximum stimulation of LH release by GnRH was observed at 13.00 h of pro-oestrus. From these studies, it is concluded that pituitary responsiveness to exogenous GnRH during pro-oestrus parallels the changes in the content of oestrogen receptors in the cytosol and nucleus.


Endocrinology ◽  
2013 ◽  
Vol 154 (1) ◽  
pp. 308-319 ◽  
Author(s):  
Laura E. Ellestad ◽  
Tom E. Porter

Glucocorticoids play a role in functional differentiation of pituitary somatotrophs and lactotrophs during embryogenesis. Ras-dva was identified as a gene regulated by anterior neural fold protein-1/homeobox expressed in embryonic stem cells-1, a transcription factor known to be critical in pituitary development, and has an expression profile in the chicken embryonic pituitary gland that is consistent with in vivo regulation by glucocorticoids. The objective of this study was to characterize expression and regulation of ras-dva mRNA in the developing chicken anterior pituitary. Pituitary ras-dva mRNA levels increased during embryogenesis to a maximum on embryonic day (e) 18 and then decreased and remained low or undetectable after hatch. Ras-dva expression was highly enriched in the pituitary gland on e18 relative to other tissues examined. Glucocorticoid treatment of pituitary cells from mid- and late-stage embryos rapidly increased ras-dva mRNA, suggesting it may be a direct transcriptional target of glucocorticoids. A reporter construct driven by 4 kb of the chicken ras-dva 5′-flanking region, containing six putative pituitary-specific transcription factor-1 (Pit-1) binding sites and two potential glucocorticoid receptor (GR) binding sites, was highly activated in embryonic pituitary cells and up-regulated by corticosterone. Mutagenesis of the most proximal Pit-1 site decreased promoter activity in chicken e11 pituitary cells, indicating regulation of ras-dva by Pit-1. However, mutating putative GR binding sites did not substantially reduce induction of ras-dva promoter activity by corticosterone, suggesting additional DNA elements within the 5′-flanking region are responsible for glucocorticoid regulation. We have identified ras-dva as a glucocorticoid-regulated gene that is likely expressed in cells of the Pit-1 lineage within the developing anterior pituitary gland.


1989 ◽  
Vol 121 (3) ◽  
pp. 513-519 ◽  
Author(s):  
D. G. Rosental ◽  
G. A. Machiavelli ◽  
A. C. Cherñavsky ◽  
N. Sterin Speziale ◽  
J. A. Burdman

ABSTRACT Two inhibitors of prostaglandin synthesis, indomethacin and aspirin, blocked the increase of oestrogen-binding sites in the nuclear subcellular fraction, an increase which occurs after the administration of oestradiol. Consequently the biological effects of oestrogens in the anterior pituitary gland of the rat (prolactin synthesis, concentration of progesteronebinding sites and cell proliferation) are diminished. The anterior pituitary gland synthesized prostaglandin F2α (PGF2α), PGE2 and PGD2 from arachidonic acid. This synthesis was blocked when indomethacin was added to the culture media. Oestrogen increased the concentration of PGE2: an increase that was partially prevented by indomethacin. Prostaglandins may have an important role on the effects of oestrogen in the anterior pituitary gland of the rat. Journal of Endocrinology (1989) 121, 513–519


1989 ◽  
Vol 121 (1) ◽  
pp. 67-74 ◽  
Author(s):  
M. C. Macnamee ◽  
P. J. Sharp

ABSTRACT An assessment was made of the possible role of hypothalamic dopamine in the regulation of changes in plasma prolactin and LH in laying and broody bantam hens. Specific dopamine-binding sites were identified, using [3H]domperidone, in the anterior pituitary gland and in the anterior and posterior hypothalamus. The mean concentrations of dopamine-binding sites in both parts of the hypothalamus were 59–66 fmol/mg protein and did not differ between laying and incubating hens. The concentration of dopamine binding sites in the anterior pituitary gland was significantly (P<0·001) greater in laying than in incubating hens (278 ± 46 compared with 420 ± 32 fmol/mg protein, n = 5). The turnover rates of dopamine were compared in the anterior and posterior hypothalami of laying, incubating and nest-deprived hens. The turnover rates were estimated from the rate of accumulation of dopamine after inhibiting its catabolism using the monoamine oxidase inhibitor, pargyline, or by measuring the ratio of the concentrations of dopamine and its major metabolite, homovanillic acid. Both methods gave the same results. The turnover of dopamine was increased in the anterior but not posterior hypothalamus of incubating hens when compared with laying or nest-deprived hens. These results show, for the first time in birds, that the anterior pituitary gland contains specific binding sites for dopamine and that the concentration of these binding sites is inversely related to the concentration of plasma prolactin. The marked increase in dopaminergic activity in the anterior hypothalamus of incubating hens may stimulate the release of unidentified prolactin-releasing factors and/or inhibit the release of LH by exerting an inhibitory influence in the area of the hypothalamus containing LHRH cell bodies. Journal of Endocrinology (1989) 121, 67–74


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