Stimulation of aromatase activity in the fetal rat testis by cyclic AMP and FSH

1988 ◽  
Vol 118 (3) ◽  
pp. 485-489 ◽  
Author(s):  
J.-P. Weniger ◽  
A. Zeis
Keyword(s):  
Cyclic Amp ◽  
Specific Activity ◽  
Isotopic Dilution ◽  
Aromatase Activity ◽  
Dibutyryl Cyclic Amp ◽  
Rat Testis ◽  
Fetal Rat ◽  
Fetal Rats ◽  
Stimulation Of

ABSTRACT The effect of dibutyryl cyclic AMP and FSH on oestrogen biosynthesis was investigated in testes from 18- to 21-day-old fetal rats cultured in vitro in the presence of tritiated testosterone. Oestrone and oestradiol concentrations were measured by determination of constant specific activity after isotopic dilution. Dibutyryl cyclic AMP and FSH markedly stimulated the conversion of testosterone into both oestrone and oestradiol at all stages studied. Oestradiol synthesis was stimulated by two- to sevenfold, while stimulation of oestrone synthesis was even greater. The results demonstrate that the aromatase enzyme system of the fetal rat testis responds to cyclic AMP and FSH. J. Endocr. (1988) 118, 485–489

Stimulation of aromatase activity in the fetal rat gonads by cAMP and FSH

1988 ◽  
Vol 119 (3) ◽  
pp. 381-385 ◽  
Author(s):  
J.-P. Weniger ◽  
A. Zeis
Keyword(s):  
Specific Activity ◽  
Isotopic Dilution ◽  
Aromatase Activity ◽  
Fetal Rat ◽  
Estrogen Synthesis ◽  
Fetal Rats ◽  
Stimulation Of ◽  
Constant Specific Activity

Abstract. The gonads from 17- to 21-day-old fetal rats were cultured in vitro in the presence of [3H]testosterone and in the presence or absence of cAMP or FSH, and estrone and estradiol formed were measured by double isotopic dilution and recrystallization to constant specific activity. Estrogen synthesis by testes was stimulated by both cAMP and FSH as early as at 18 days of gestation. FSH did not enhance aromatase activity in ovaries, although cAMP did. It is remarkable that FSH controls estrogen synthesis in the testis earlier than in the ovary.

Modulation of human DNA methyltransferase activity and mRNA levels in the monoblast cell line U937 induced to differentiate with dibutyryl cyclic AMP and phorbol ester

1993 ◽  
Vol 11 (2) ◽  
pp. 191-200 ◽  
Author(s):  
P Soultanas ◽  
P D Andrews ◽  
D R Burton ◽  
D P Hornby
Keyword(s):  
Steady State ◽  
Cyclic Amp ◽  
Gene Transcription ◽  
Phorbol Ester ◽  
Specific Activity ◽  
Mrna Levels ◽  
Dibutyryl Cyclic Amp ◽  
Nuclear Extracts ◽  
Steady State Levels ◽  
Stimulation Of

ABSTRACT The regulation of DNA (cytosine-5) methyltransferase (DNA MeTase) enzyme activity and gene expression was examined in the monoblastoid U937 cell line induced to differentiate with either dibutyryl cyclic AMP (dbcAMP) or phorbol ester. dbcAMP treatment was found to cause the rapid (<4 h) suppression of DNA MeTase specific activity, with no DNA MeTase activity detectable after 10 h. Equally, no DNA MeTase activity was detectable in nuclear extracts of fresh peripheral blood monocytes. Using both a U937 DNA MeTase cDNA and a mouse DNA MeTase cDNA as probes, steady-state levels of DNA MeTase mRNA were found to decline sharply between 4 and 15 h after dbcAMP treatment. No DNA MeTase mRNA was detectable after 20 h of dbcAMP treatment. Nuclear run-on analysis showed there to be only a small (40%) suppression of DNA MeTase gene transcription in cells treated with dbcAMP for 24 h, implying a role for post-transcriptional processes in the regulation of DNA MeTase mRNA levels. The observed decline in DNA MeTase activity/mRNA levels appeared to precede the dbcAMP-induced arrest in DNA replication, as judged by the incorporation of tritiated thymidine into DNA. In contrast to the effect of dbcAMP, treatment of U937 cells with the phorbol ester 12-O-tetradecanoyl phorbol-13-acetate (TPA) led to an overall stimulation of DNA MeTase specific activity. The TPA response was found to be complex and broadly consisted of an early (0–15 h) burst of DNA MeTase activity followed by a more gradual sustained increase in DNA MeTase activity after prolonged (16–40 h) TPA treatment. The early phase of high DNA MeTase activity was not mirrored by an increase in steady-state levels of DNA MeTase mRNA, as judged by Northern blot analysis. However, a substantial induction of DNA MeTase mRNA levels was observed after 20–24 h of TPA treatment. Nuclear run-on analysis showed this not to be due to any significant increase in DNA MeTase gene transcription. The observed increases in DNA MeTase activity/mRNA levels were observed whilst cells were undergoing deproliferation. Interestingly, the addition of TPA and more physiological protein kinase C (PKC) activators, such as diacylglycerol and phosphatidylserine, to DNA MeTase-enriched nuclear extracts generated a 4·5-fold and a 1·5-fold increase in DNA MeTase specific activity respectively. The TPA-induced stimulation of DNA MeTase activity could be inhibited by the PKC inhibitor H-9, implicating a role for PKC in the regulation of DNA MeTase activity in vivo.

scholarly journals Regulation of the synthesis of lutropin-induced protein in rat testis Leydig cells

1978 ◽  
Vol 170 (1) ◽  
pp. 9-15 ◽  
Author(s):  
Felix H. A. Janszen ◽  
Brian A. Cooke ◽  
Maria J. A. Van Driel ◽  
Henk J. Van Der Molen
Keyword(s):  
Protein Synthesis ◽  
Cyclic Amp ◽  
Leydig Cells ◽  
Actinomycin D ◽  
Polyacrylamide Gel Electrophoresis ◽  
Phosphodiesterase Inhibitor ◽  
Dibutyryl Cyclic Amp ◽  
Rat Testis ◽  
Stimulation Of

The mechanism of action of lutropin on the stimulation of the synthesis of a specific lutropin-induced protein in rat testis Leydig cells was investigated. Lutropin-induced protein has a mol.wt. of approx. 21000 and is detected by labelling the Leydig-cell proteins with [35S]methionine, followed by separation by polyacrylamide-gel electrophoresis and radioautography of the dried gel. The incorporation of35S into lutropin-induced protein was used as an estimate for the synthesis of the protein. Incubation of Leydig cells with dibutyryl cyclic AMP or cholera toxin also resulted in the stimulation of synthesis of the protein. Synthesis of lutropin-induced protein, when maximally stimulated with 100ng of lutropin/ml, could not be stimulated further by addition of dibutyryl cyclic AMP. Addition of 3-isobutyl-1-methylxanthine, a phosphodiesterase inhibitor, further increased synthesis of the protein in the presence of a submaximal dose of lutropin (10ng/ml) but not in the absence of lutropin or with maximal amounts of lutropin (100 and 1000ng/ml). Actinomycin D prevented the effect of lutropin on the stimulation of lutropin-induced protein synthesis when added immediately or 1h after the start of the incubation, but not when added after 5–6h. This is interpreted as reflecting that, after induction of mRNA coding for lutropin-induced protein, lutropin had no influence on the synthesis of the protein in the presence of actinomycin D. Synthesis of the protein was also stimulated in vivo by injection of choriogonadotropin into rats 1 day after hypophysectomy, and the time course of this stimulation of lutropin-induced protein synthesis in vivo was similar to that obtained by incubating Leydig cells in vitro with lutropin. From these results it is concluded that stimulation of lutropin-induced protein synthesis by lutropin is most probably mediated by cyclic AMP and involves synthesis of mRNA.

A quantitative and interspecific test for biological activity of anti-mullerian hormone: the fetal ovary aromatase assay

Development ◽  
1992 ◽  
Vol 114 (3) ◽  
pp. 721-727 ◽  
Author(s):  
N. di Clemente ◽  
S. Ghaffari ◽  
R.B. Pepinsky ◽  
C. Pieau ◽  
N. Josso ◽  
...  
Keyword(s):  
Biological Activity ◽  
Chick Embryo ◽  
Cyclic Amp ◽  
Species Specificity ◽  
Human Protein ◽  
Aromatase Activity ◽  
Fetal Rat ◽  
Fetal Ovary ◽  
Quantitative Bioassay

Anti-Mullerian hormone (AMH), also known as Mullerian-inhibiting substance or factor, has previously been shown to sex-reverse the steroidogenic pattern of fetal mammalian ovaries through repression of aromatase biosynthesis. Study of the ontogeny of the response of cyclic AMP-stimulated aromatase activity of rat fetal ovaries to AMH has allowed us to develop a quantitative bioassay for the hormone. Linear responses as a function of the logarithm of AMH concentration were observed over ranges of 0.2-7.5 micrograms/ml for the bovine protein and 0.15-2 micrograms/ml for the human protein, with a maximal decrease in aromatase activity of 90% for both proteins. Under the same in vitro conditions, AMH treatment did not affect cyclic AMP-stimulated fetal rat testicular aromatase activity. Partially purified chick AMH also decreased rat ovarian aromatase activity, allowing us to use this test to study AMH ontogeny in chick gonads. Analysis of the species specificity of AMH repression of ovarian aromatase activity indicated that turtle and rat fetal ovaries responded to AMH of other vertebrate classes, whereas aromatase activity of chick embryo ovaries could be repressed only by the homospecific hormone.

Stimulation of calcitonin synthesis and release in vitro by calcium and dibutyryl cyclic AMP

Nature ◽  
1974 ◽  
Vol 248 (5446) ◽  
pp. 343-344 ◽  
Author(s):  
NORMAN H. BELL ◽  
SHERRY QUEENER
Keyword(s):  
Cyclic Amp ◽  
Dibutyryl Cyclic Amp ◽  
Release In Vitro ◽  
Stimulation Of

scholarly journals Modifications of major aspects of myocardial ribonucleic acid metabolism as a response to noradrenaline. Behaviour of polyadenylate polymerase and ribonucleic acid polymerase, acetylation of histones and rate of synthesis of polyamines

1977 ◽  
Vol 168 (3) ◽  
pp. 333-340 ◽  
Author(s):  
A Casti ◽  
A Corti ◽  
N Reali ◽  
G Mezzetti ◽  
G Orlandini ◽  
...  
Keyword(s):  
Cyclic Amp ◽  
Ribonucleic Acid ◽  
Acid Metabolism ◽  
Specific Radioactivity ◽  
Rabbit Heart ◽  
Polymerase Activity ◽  
Dibutyryl Cyclic Amp ◽  
General Increase ◽  
Stimulation Of

Noradrenaline added to perfused rabbit heart previously perfused with labelled precursors causes, after 2.5 and 5.0 min, a general increase of specific radioactivity or RNA in subcellular fractions, but no augmentation of acetylation of F2a2 and F2a1 histone fractions and no stimulation of DNA-dependent RNA polymerase activities. Synthesis of spermidine and spermine is enhanced at 10.0 min of treatment, when there is also a fall in specific radioactivity of RNA. The cytoplasmic Mn2+-stimulated polyadenylate polymerase activity is strongly enhanced 30s to 2.5 min after injection of noradrenaline or of dibutyryl cyclic AMP. Both the cyclic nucleotide and noradrenaline have no influence in vitro on the polyadenylate polymerase reaction.

Stimulation of 3′,5′-cyclic AMP and testosterone production in rat testis in vitro

FEBS Letters ◽  
1972 ◽  
Vol 24 (3) ◽  
pp. 251-254 ◽  
Author(s):  
F.F.G. Rommerts ◽  
B.A. Cooke ◽  
J.W.C.M. van der Kemp ◽  
H.J. van der Molen
Keyword(s):  
Cyclic Amp ◽  
Rat Testis ◽  
Testosterone Production ◽  
Stimulation Of
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