SEPARATION OF A LABELLED FRAGMENT FROM PROTEIN SYNTHESIZED IN VITRO BY THE PARS INTERMEDIA OF THE MOUSE PITUITARY GLAND

1977 ◽  
Vol 75 (1) ◽  
pp. 181-182
Author(s):  
H. M. ISHERWOOD ◽  
V. F. THORNTON
Keyword(s):  
Molecular Weight ◽  
Pituitary Gland ◽  
Pars Intermedia ◽  
Biosynthetic Activity ◽  
Cellulose Acetate Electrophoresis ◽  
King's College ◽  
Large Molecular Weight ◽  
Pituitary Glands ◽  
Mouse Pituitary

Department of Anatomy, King's College, London, WC2R 2LS (Received 12 May 1977) The biosynthetic activity of the pars intermedia of the mouse pituitary gland was investigated by studying the fate of labelled amino acids incorporated into relatively large-molecular-weight products (Thornton & Isherwood, 1975). It was reported that label was actively incorporated in vitro into a protein (referred to as 'labelled P1') with a molecular weight of about 75 000 (Isherwood & Thornton, 1977). However, more recent observations suggest that 'labelled P1' is a complex between a protein and a labelled peptide. The purpose of this communication is to give a brief account of some of the findings which led to this conclusion. Full details of the incubation and cellulose acetate electrophoresis procedures are given in Isherwood & Thornton (1977). Posterior pituitary glands from male, Schofield mice were incubated in media containing [3H]leucine and [3H]phenylalanine (50 μCi/ml). In one experiment, posterior

PROTEIN BIOSYNTHESIS IN VITRO BY THE PARS INTERMEDIA OF THE MOUSE PITUITARY GLAND

1977 ◽  
Vol 72 (2) ◽  
pp. 173-179
Author(s):  
H. ISHERWOOD ◽  
V. F. THORNTON
Keyword(s):  
Amino Acids ◽  
Molecular Weight ◽  
Protein Biosynthesis ◽  
Pars Intermedia ◽  
Secretory Product ◽  
Posterior Pituitary ◽  
Short Term ◽  
Pituitary Glands ◽  
Mouse Pituitary

SUMMARY During short-term incubations of isolated posterior pituitary glands of the mouse, isotopically labelled amino acids were incorporated into protein by the cells of the pars intermedia. Using labelled leucine, 5–10% of incorporated label was found in a protein (P1), with a molecular weight of about 75000. Protein P1 could be isolated from both fresh and incubated tissue, and was a normal and indeed major, secretory product of the pars intermedia, constituting more than 50% of the protein present.

Effect of Estrogen on Melanocortin-3 Receptor mRNA Expression in Mouse Pituitary Glands in vivo and in vitro

2004 ◽  
Vol 80 (3) ◽  
pp. 143-151 ◽  
Author(s):  
Ryusei Matsumura ◽  
Sakae Takeuchi ◽  
Sumio Takahashi
Keyword(s):  
Mrna Expression ◽  
Receptor Mrna ◽  
Pituitary Glands ◽  
Mouse Pituitary

In-vivo and in-vitro secretion of prolactin by lactating rat adenohypophyses as a function of intracellular age

1984 ◽  
Vol 101 (1) ◽  
pp. 27-32 ◽  
Author(s):  
F. Mena ◽  
G. Martínez-Escalera ◽  
C. Clapp ◽  
C. E. Grosvenor
Keyword(s):  
Pituitary Gland ◽  
Incubation Period ◽  
Gel Electrophoresis ◽  
Polyacrylamide Gel Electrophoresis ◽  
Polyacrylamide Gel ◽  
Pituitary Glands ◽  
H 26

ABSTRACT Adenohypophysial prolactin of lactating rats was pulse-labelled by [3H]leucine injected i.v. at the time of removal of the pups. The [3H]prolactin concentration in the pituitary gland, analysed by polyacrylamide-gel electrophoresis, progressively fell as the time from labelling to removal of the pituitary gland increased from 8 to 24 h, which suggests that there was a loss of hormone as it aged within the gland. Suckling effectively provoked the depletion–transformation of total and [3H]prolactin (extracted at pH 7·2) when applied after 8 h but not when applied after either 16 or 24 h after removing the pups. In rats whose pups were removed for 8 h, suckling also depleted–transformed [3H]prolactin labelled 4 h, but not that labelled 1 h before suckling. The pituitary glands of other lactating rats were labelled with [3H]leucine injected i.v. at various times before removing the glands and incubating them in medium 199. The secretion into the medium of [3H]prolactin labelled either 4, 8, 16 or 24 h beforehand was maximal during the first 30 min then declined from 30 to 240 min of incubation. However, secretion of prolactin labelled 1 h and 10 min beforehand reached a maximum after 0·5–1 h and 2 h of incubation respectively, then remained constant during the remainder of the 4-h incubation period. The total 4-h secretion of [3H]prolactin was greatest (65% of preincubation concentration) from those glands labelled 4 h before in contrast to those labelled 10 min (15%) or 1 (38%), 8 (34%), 16 (18%) or 24 h (26%) before incubation. Taken together, these data suggest that prolactin synthesized 4 h earlier is more likely to be released in response to physiological stimuli than is more recently formed prolactin or prolactin which has remained in the pituitary gland for 16 h or longer. J. Endocr. (1984) 101, 27–32

The functional significance of glycosylation of proopiomelanocortin in melanotrophs of the mouse pituitary gland

1985 ◽  
Vol 107 (3) ◽  
pp. 365-374 ◽  
Author(s):  
B. G. Jenks ◽  
A. G. H. Ederveen ◽  
J. H. M. Feyen ◽  
A. P. van Overbeeke
Keyword(s):  
Pituitary Gland ◽  
Functional Significance ◽  
Peptide Hormones ◽  
Terminal Region ◽  
Pars Intermedia ◽  
Apparent Effect ◽  
Glycoprotein Precursor ◽  
Tunicamycin Treatment ◽  
Mouse Pituitary

ABSTRACT Pro-opiomelanocortin (POMC) is a glycoprotein precursor for a number of neuropeptides and peptide hormones. The functional significance of the glycosylation of POMC has never been established. Using the antibiotic tunicamycin to block glycosylation of the prohormone in the mouse pars intermedia, we have compared processing of non-glycosylated prohormone with that of glycosylated prohormone in pulse-chase experiments. The peptides produced from non-glycosylated prohormone were shown to be correct cleavage products. Therefore it was concluded that, with the possible exception of peptides from the N-terminal region of the prohormone, the carbohydrate on POMC plays no role in directing cleavage or in protecting the prohormone from random proteolysis. Tunicamycin treatment retarded N-terminal acetylation of melanotrophin but had no apparent effect on acetylation of β-endorphin. The mouse pars intermedia synthesizes two forms of POMC which differ in their degree of glycosylation. Our results indicated that, during secretion, the melanotrophs make no distinction between peptides derived from the two prohormones. J. Endocr. (1985) 107, 365–374

Differential Expression of Cytokeratins 8 and 20 Distinguishes Craniopharyngioma From Rathke Cleft Cyst

2002 ◽  
Vol 126 (10) ◽  
pp. 1174-1178 ◽  
Author(s):  
Wei Xin ◽  
Mark A. Rubin ◽  
Paul E. McKeever
Keyword(s):  
Molecular Weight ◽  
Differential Expression ◽  
Expression Patterns ◽  
Primary Diagnosis ◽  
Pars Intermedia ◽  
Rathke Cleft Cyst ◽  
Cytokeratin Expression ◽  
Pituitary Glands ◽  
Clinically Significant ◽  
Difficult Cases

Abstract Background.—Craniopharyngiomas are epithelial neoplasms usually located in the sellar and suprasellar regions. Distinguishing craniopharyngioma from Rathke cleft cyst is sometimes difficult, and the distinction is clinically significant because Rathke cleft cysts have a better prognosis than craniopharyngiomas. Design.—We retrieved 10 cases with a primary diagnosis of craniopharyngioma and 5 cases with a diagnosis of Rathke cleft cyst for analysis. Five cases of normal pars intermedia of pituitary glands from autopsy served as controls. We evaluated the expression patterns of a broad range of low– to intermediate–molecular weight cytokeratins (CK7, CK8, CK10, CK17, CK18, CK19, and CK20) and high–molecular weight cytokeratins (K903: a combination of CK1, CK5, CK10, and CK14; and CK5/6) in these cases. Results.—Craniopharyngiomas had a cytokeratin expression pattern distinct from that of Rathke cleft cysts and pituitary gland pars intermedia: craniopharyngiomas did not express cytokeratins 8 and 20, whereas Rathke cleft cysts and pars intermedia of pituitary glands both expressed cytokeratins 8 and 20. Conclusion.—The differential expression of cytokeratins distinguishes between craniopharyngioma and Rathke cleft cyst, and this difference could be useful for identifying craniopharyngioma in difficult cases in which only a small biopsy is available. The different cytokeratin profiles of craniopharyngioma and Rathke cleft cyst suggest that these lesions do not come from the same origin, or that they come from a different developmental stage of the pouch epithelium.

Homologous and heterologous regulation of somatostatin-binding sites on chicken adenohypophysial membranes

1990 ◽  
Vol 127 (3) ◽  
pp. 417-425 ◽  
Author(s):  
S. Harvey ◽  
J. S. Baidwan ◽  
D. Attardo
Keyword(s):  
Pituitary Gland ◽  
Binding Sites ◽  
Recombinant Dna ◽  
Inhibitory Effect ◽  
Partial Recovery ◽  
Caudal Lobe ◽  
Direct Inhibitory Effect ◽  
Pituitary Glands

ABSTRACT Binding of 125I-labelled [Tyr1]-somatostatin (125I-[Tyr1]-SRIF) to pituitary caudal lobe membranes was suppressed in immature chickens 1 and 2 h after i.v. administration of unlabelled SRIF at concentrations of 1–100 μg/kg. In-vitro preincubation of chicken pituitary glands for 0·5–4·0 h with 0·1 μmol SRIF/l similarly reduced the binding of 125I-[Tyr1]-SRIF to caudal lobe membrane preparations. After a 4-h incubation in 0·1 mmol SRIF/l, the withdrawal of SRIF from the incubation media was accompanied 4 h later by a partial recovery in the binding of 125I-[Tyr1]-SRIF to pituitary membranes. Passive immunoneutralization of endogenous SRIF resulted in a prompt (within 1 h) and sustained (for at least 24 h) suppression of 125I-[Tyr1]-SRIF binding to pituitary membranes. The i.m. administration of cysteamine (300 mg/kg) to 12-week-old birds depleted hypothalamic SRIF stores and decreased the density of 125I-[Tyr1]-SRIF-binding sites in the caudal and cephalic lobes of the chicken pituitary gland. The reduction in SRIF content and in SRIF-binding sites occurred within 1 h of cysteamine administration and was maintained for at least 24 h. In 6-week-old birds, cysteamine (300 mg/kg) administration suppressed pituitary binding of 125I-[Tyr1]-SRIF for at least 5 days. Circulati concentrations of GH were markedly decreased 1 and 4 h after cysteamine injection, but not after 24 h. Pituitary binding sites for 125I-[Tyr1]-SRIF were not affected by pretreatment of pituitary glands for 2–12 h in vitro with thyroxine or oestradiol-17β (1 nmol/l–10 μmol/l) or with ovine GH or recombinant DNA-derived chicken GH (1–100 μg/ml in vitro and 100–1000 μg/kg in vivo). Ovine prolactin, at concentrations of 1–100 μg/ml was also without effect on 125I-[Tyr1]-SRIF binding to pituitary membranes following a 2- or 4-h incubation with pituitary glands. Pituitary binding sites for 125I-[Tyr1]-SRIF were, however, increased after a 24-h incubation with 1 μmol tri-iodothyronine (T3)/l in vitro and 4 and 24 h after the administration of T3 (100–1000 μg/kg) in vivo. Although T3 had no direct inhibitory effect on 125I-[Tyr1]-SRIF binding to pituitary membranes, binding was suppressed 1 and 2 h after the in-vivo administration of T3 at concentrations of 100–1000 μg/kg. These results therefore demonstrate homologous and heterologous regulation of SRIF-binding sites in the chicken pituitary gland. Journal of Endocrinology (1990) 127, 417–425

scholarly journals In vitro biosynthesis of beta-endorphin, gamma-lipoprotein, and beta-lipotropin by the pars intermedia of beef pituitary glands.

1977 ◽  
Vol 74 (10) ◽  
pp. 4276-4280 ◽  
Author(s):  
P. Crine ◽  
S. Benjannet ◽  
N. G. Seidah ◽  
M. Lis ◽  
M. Chretien
Keyword(s):  
Pars Intermedia ◽  
Beta Endorphin ◽  
Pituitary Glands ◽  
In Vitro Biosynthesis

miR-375 acts as a novel factor modulating pituitary prolactin synthesis through Rasd1 and Esr1

2021 ◽  
Author(s):  
Jinglin Zhang ◽  
Jie Gao ◽  
Di Zhang ◽  
Hui Liu ◽  
Kemian Gou ◽  
...  
Keyword(s):  
Pituitary Gland ◽  
In Vitro Study ◽  
Luciferase Reporter ◽  
Pituitary Hormone ◽  
Hormone Synthesis ◽  
Protein Levels ◽  
Bioinformatic Tools ◽  
Mouse Pituitary ◽  
Prolactin Synthesis

Prolactin (PRL) is a pituitary hormone that regulates multiple physiological processes. However, the mechanisms of PLR synthesis have not been fully elucidated. The aims of the present study were to study the functions and the related mechanisms of miR-375 regulating PRL synthesis. We initially found that miR-375 mainly expressed in the lactotrophs of mouse pituitary gland. To identify the function of miR-375 in the pituitary gland, the miR-375 knockout mice were generated by using Crispr/Cas9 technique. The results showed that miR-375 knockout resulted in the decline of pituitary PRL mRNA and protein levels by 75.7% and 60.4% respectively, and the serum PRL level reduced about 46.1%, but had no significant effect on FSH, LH and TSH. Further, we identified that Estrogen receptor 1 (alpha) (Esr1) was a downstream molecule of miR-375. The real-time PCR and western blot results showed that ESR1 mRNA and protein levels markedly decreased by 40.9% and 42.9% in the miR-375 knockout mouse pituitary, and these were subsequently confirmed by the in vitro study using transfections of miR-375 mimics and inhibitors in pituitary lactotroph GH4 cells. Further, Rasd1 was predicted by bioinformatic tools and proved to be the direct target of miR-375 in lactotrophs using dual-luciferase reporter assay. Rasd1-siRNA transfection results revealed the negative effect of Rasd1 in regulating ESR1. Collectively, the results presented here demonstrate that miR-375 positively modulates PRL synthesis through Rasd1 and Esr1, which are crucial for understanding the regulating mechanisms of pituitary hormone synthesis.

Isolation and characterization of β-lipolytic hormone from porcine pituitary gland

1970 ◽  
Vol 48 (9) ◽  
pp. 1017-1021 ◽  
Author(s):  
C. Gilardeau ◽  
M. Chrétien
Keyword(s):  
Molecular Weight ◽  
Amino Acid ◽  
Pituitary Gland ◽  
Amino Acid Composition ◽  
Biological Activities ◽  
Terminal Amino Acid ◽  
Isolation And Characterization ◽  
Pituitary Glands ◽  
Terminal Amino

A lipolytic substance was isolated from porcine pituitary glands. It's amino acid composition, molecular weight, N-terminal amino acid, isoelectric point, and biological activities are reported. These results are compared to the corresponding values of sheep β-lipolytic hormone.

Hypothalamic dopamine and catechol oestrogens in rats with spontaneous pituitary tumours

1983 ◽  
Vol 96 (2) ◽  
pp. 347-352 ◽  
Author(s):  
R. A. Prysor-Jones ◽  
J. J. Silverlight ◽  
J. S. Jenkins
Keyword(s):  
Pituitary Gland ◽  
Plasma Prolactin ◽  
Pituitary Tumours ◽  
Dopamine Concentration ◽  
Rat Pituitary ◽  
Pituitary Glands ◽  
Normal Rat ◽  
Old Rats ◽  
Hypothalamic Dopamine

Dopamine concentration within the hypothalamus and its depletion after the administration of α-methyl-para-tyrosine were measured in young rats and compared with values obtained in aged animals with and without spontaneously occurring pituitary tumours. Old rats had significantly reduced hypothalamic dopamine concentrations and there was less depletion of dopamine compared with young animals but there were no differences between tumorous and non-tumorous animals. Hyperprolactinaemia induced in young animals caused a much greater depletion of hypothalamic dopamine than in old tumorous rats with comparable plasma prolactin concentrations. The catechol oestrogen 2-hydroxyoestradiol inhibited the release of prolactin from normal rat pituitary glands in vitro but measurement of catechol oestrogens in the hypothalamus showed no differences between young and old tumorous or non-tumorous rats. It is concluded that reduced dopamine concentration and an impaired response to hyperprolactinaemia in old rats may facilitate the growth of prolactin-secreting tumours arising in the pituitary gland.

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