Differential regulation of FSH and inhibin gene expression and synthesis by testosterone in immature and mature male rats

1993 ◽  
Vol 137 (1) ◽  
pp. 69-79 ◽  
Author(s):  
A. Perheentupa ◽  
M. Bergendahl ◽  
F. H. de Jong ◽  
I. Huhtaniemi
Keyword(s):  
Gene Expression ◽  
Combined Treatment ◽  
Male Rats ◽  
Mrna Levels ◽  
Partial Recovery ◽  
Β Subunit ◽  
Adult Rats ◽  
Testosterone Treatment ◽  
Subunit Mrna ◽  
Immature Rats

ABSTRACT Direct effects of testosterone on gonadotrophins at the pituitary level were studied in intact and castrated immature (age 10 days) and mature (70 days) male rats. Gonadotrophin-releasing hormone action was blocked by treatment with a potent GnRH antagonist, Ac-d-pClPhe-d-pClPhe-d-Trp-Ser-Tyr-d-Arg-Leu-Arg-Pro-d-Ala-NH2CH3COOH (Ant; Organon 30276; 1·0 mg/kg body weight per day) injected subcutaneously. Silicone elastomer capsules were used for the testosterone treatment. Both treatments commenced on the day of orchiectomy and lasted for 7 days. In adult male rats Ant treatment suppressed serum testosterone from 9·5 ± 2·5 (s.e.m.) nmol/l to below the limit of detection (< 0·10 nmol/l; P < 0·01), and the testosterone implants reversed the decrease. Treatment with Ant decreased the pituitary content of FSH-β subunit mRNA in intact and orchiectomized rats to 14% of their respective controls (P < 0·01). These levels were increased to 80–81% of controls (not significant) in both groups by combined treatment with testosterone and Ant. Orchiectomy alone increased FSH-β subunit mRNA by 202% (P < 0·01). In intact immature rats Ant treatment decreased the level of pituitary FSH-β subunit mRNA to 21% (P<0·01), and a partial recovery (P < 0·01) to 42% of controls was observed with combined Ant + testosterone treatment. In contrast, in orchiectomized immature rats, where ANT decreased FSH-β subunit levels to 48% of controls (P < 0·01), testosterone was able to reverse these mRNA levels completely (114% of controls). No evidence for the direct pituitary effects of testosterone were found in the mRNA of the common α or LH-β subunits. In adult rats, the testicular inhibin α and βA subunit mRNA levels were increased (P < 0·01) by Ant + testosterone compared with Ant-treated animals, but there were no differences in serum immunoreactive inhibin between any of the uncastrated adult groups. In intact immature rats, Ant + testosterone treatment increased (P < 0·01) inhibin βA subunit mRNA levels compared with controls and Ant-treated animals. Ant decreased the level of peripheral inhibin immunoreactivity from 8·3 ± 2·0 U/ml to 2·1 ± 0·4 U/ml (P < 0·01) and testosterone reversed it to 5·8 ± 0·6 U/ml (not significant). In conclusion, our observations indicated that testosterone is able to stimulate FSH gene expression and secretion directly in immature and adult rats, but the testosterone response is enhanced at both ages by orchiectomy, even more so in the immature rat. This may be explained by age differences in the contribution of testicular inhibin to the regulation of FSH synthesis and secretion at the pituitary level. Journal of Endocrinology (1993) 137, 69–79

scholarly journals Effect of IGF-I and PDGF administered in vivo on the expression of osteoblast-related genes in old rats

2002 ◽  
Vol 174 (1) ◽  
pp. 63-70 ◽  
Author(s):  
H Tanaka ◽  
A Wakisaka ◽  
H Ogasa ◽  
S Kawai ◽  
CT Liang
Keyword(s):  
Gene Expression ◽  
Growth Factors ◽  
Mrna Expression ◽  
Combined Treatment ◽  
Mrna Levels ◽  
Adult Rats ◽  
Igf I ◽  
Old Rats ◽  
Osteoblast Markers ◽  
Marrow Ablation

In order to establish the cellular basis for using growth factors as possible therapeutic agents for the age-dependent deficit in bone formation activity, we examined the individual and combined effects of IGF-I and/or platelet-derived growth factor (PDGF) on the gene expression of osteoblast-related markers in male rats. The expression of osteoblast markers was examined in the femurs of adult and old rats following marrow ablation, which amplifies gene expression activity. The mRNA levels of collagen(alpha1) (I) (COLI), alkaline phosphatase (AP), osteopontin (OP) and osteocalcin (OC) were significantly lower in the old as compared with the adult rats. To determine whether growth factors can abolish the age-related deficits in mRNA expression in old bone, PDGF and/or IGF-I were infused directly into the right femur for 5 days following marrow ablation. The contralateral femur was infused with vehicle only and used as a control. PDGF stimulated the expression of OP mRNA in both adult and old rats, whereas COLI, AP and OC mRNAs were not affected. IGF-I infusion did not have a significant effect on mRNA expression in adult rats. In contrast, treatment with IGF-I significantly enhanced the mRNA levels of COLI, AP and OP in old rats. To examine whether the combination of both factors could affect the expression of osteoblast markers synergistically, PDGF and IGF-I were infused together. In adult bones, the combined treatment with PDGF and IGF-I caused a slight increase in the level of OP gene expression but no change in AP, OC or COLI genes. Although neither IGF-I nor PDGF alone was effective in stimulating the expression of OC, the combined treatment in old bones enhanced OC expression significantly. The expression of COLI, AP and OP was also stimulated, but the stimulation was no different from that of IGF-I alone. In PDGF plus IGF-I treatment with a high dose, no dose-response effects were observed. Within the limits of the present study, it is suggested that IGF-I and, to a much lesser extent, PDGF may partially restore the deficit in the expression of osteoblast markers in old bones, and that the combination of both factors is slightly better than IGF-I alone in stimulating OC expression.

Gonadal regulation of pituitary hormone mRNA levels in male rats

1988 ◽  
Vol 1 (1) ◽  
pp. 61-68 ◽  
Author(s):  
S. D. Abbot ◽  
K. Docherty ◽  
R. N. Clayton
Keyword(s):  
Gene Expression ◽  
Male Rats ◽  
Male Rat ◽  
Pituitary Hormone ◽  
Mrna Levels ◽  
Subunit Gene ◽  
Α Subunit ◽  
Intact Control ◽  
Subunit Mrna ◽  
Serum Lh

ABSTRACT The control of anterior pituitary hormone gene expression by testosterone in male rat pituitaries in vivo was investigated using dot-blot mRNA-cDNA hybridization assays. Common α subunit mRNA levels doubled by 2 days after orchidectomy and rose progressively to reach plateau levels three to four times intact control values by 2 weeks. LH-β mRNA increased significantly (≃50%) within 12h, and thereafter progressively to seven times intact control values by 3 weeks after orchidectomy. The changes in α mRNA were likely to have occurred in gonadotrophs and not thyrotrophs, since TSH-β mRNA levels were unaltered by orchidectomy. LH subunit mRNA changes were accompanied by an initial (1–4 days) decrease in pituitary LH content; thereafter, pituitary LH increased in parallel with and by a similar magnitude to the LH-β mRNA. Serum LH rises occurred before significant increases in LH subunit mRNA after orchidectomy. The lack of temporal correlation between mRNA levels and serum and pituitary LH in the early stages after removal of testosterone feedback contrasts with the good correlation when a new steady state was achieved after 3–4 weeks, and indicates differing kinetics for changes in these aspects of gonadotroph function. An inhibitory effect of testosterone on LH subunit gene expression was confirmed by prevention of the rise in α and LH-β mRNAs when treatment commenced immediately after castration. However, pituitary LH content and serum LH levels were reduced relative to control values, suggesting additional inhibitory actions of testosterone on translational and post-translational events in gonadotrophs. A stimulatory effect of testosterone on α mRNA levels was observed between 4 and 24 h after a single injection in rats castrated 2 weeks previously, no effect being seen on LH-β mRNA. The mechanism for this action remains to be elucidated. Gene specificity of testosterone action was confirmed by unaltered levels of mRNA for prolactin, GH, TSH-β subunit and actin under all experimental conditions. No changes in pituitary content of prolactin or GH were found. We conclude that regulation of LH subunit gene expression by testosterone is an important step in control of gonadotrophin synthesis and availability for release.

Expression of acetylcholine receptor mRNAs in atrophying and nonatrophying skeletal muscles of old rats

1998 ◽  
Vol 85 (5) ◽  
pp. 1903-1908 ◽  
Author(s):  
Ronald R. Gomes ◽  
Frank W. Booth
Keyword(s):  
Skeletal Muscle ◽  
Acetylcholine Receptor ◽  
Biceps Brachii ◽  
Male Rats ◽  
Brown Norway ◽  
Mrna Levels ◽  
Adult Rats ◽  
Γ Subunit ◽  
Age Related ◽  
Old Rats

We examined the age-related association in skeletal muscle between atrophy and expression of mRNAs encoding both the γ-subunit of the nicotinic acetylcholine receptor (AChR), and myogenin, a transcription factor that upregulates expression of the γ-subunit promoter. Gastrocnemius and biceps brachii muscles were collected from young (2-mo-old), adult (18-mo-old), and old (31-mo-old) Fischer 344/Brown Norway F1 generation cross male rats. In the gastrocnemius muscles of old vs. young and adult rats, lower muscle mass was accompanied by significantly elevated AChR γ-subunit and myogenin mRNA levels. In contrast, the biceps brachii muscle exhibited neither atrophy nor as drastic a change in AChR γ-subunit and myogenin mRNA levels with age. Expression of the AChR ε-subunit mRNA did not change with age in either gastrocnemius or biceps brachii muscles. Thus changes in skeletal muscle AChR γ-subunit and myogenin mRNA levels may be more related to atrophy than to chronological age in old rats.

scholarly journals Differential regulation of γ-glutamylcysteine synthetase heavy and light subunit gene expression

1997 ◽  
Vol 326 (1) ◽  
pp. 167-172 ◽  
Author(s):  
Jiaxin CAI ◽  
Zong-Zhi HUANG ◽  
Shelly C. LU
Keyword(s):  
Oxidative Stress ◽  
Gene Expression ◽  
Steady State ◽  
Mrna Level ◽  
Rat Hepatocytes ◽  
Mrna Levels ◽  
Subunit Gene ◽  
Subunit Mrna ◽  
Glutamylcysteine Synthetase ◽  
Steady State Mrna Level

γ-Glutamylcysteine synthetase (GCS) is the rate-limiting enzyme in the biosynthesis of glutathione and is composed of a heavy and a light subunit. Although the heavy subunit is enzymically active alone, the light subunit plays an important regulatory role by making the holoenzyme function more efficiently. In the current study we examined whether conditions which are known to influence gene expression of the heavy subunit also influence that of the light subunit, and the mechanisms involved. Treatment of cultured rat hepatocytes with hormones such as insulin and hydrocortisone, or plating hepatocytes under low cell density increased the steady-state mRNA level of the heavy subunit only. Treatment with diethyl maleate (DEM), buthionine sulphoximine (BSO) and t-butylhydroquinone (TBH) increased the steady state mRNA level and gene transcription rates of both subunits. These treatments share in common their ability to induce oxidative stress and activate nuclear factor κB (NF-κB). Treatment with protease inhibitors 7-amino-1-chloro-3-tosylamido-2-heptanone (TLCK) or L-1-tosylamido-2-phenylethyl chloromethyl ketone (TPCK) had no influence on the basal NF-κB and GCS subunit mRNA levels, but blocked the activation of NF-κB by DEM, BSO and TBH, and the increase in GCS heavy subunit mRNA level by BSO and TBH. On the other hand, the DEM-, BSO- and TBH-induced increase in GCS light-subunit mRNA level was unaffected by TLCK and TPCK. Thus only the heavy subunit is hormonally regulated and growth sensitive, whereas both subunits are regulated by oxidative stress. Signalling through NF-κB is involved only in the oxidative-stress-mediated changes in the heavy subunit gene expression.

Prepubertal male rats with high rates of germ-cell apoptosis present exacerbated rates of germ-cell apoptosis after serotonin depletion

2016 ◽  
Vol 28 (6) ◽  
pp. 806 ◽  
Author(s):  
Néstor Méndez Palacios ◽  
María Elena Ayala Escobar ◽  
Maximino Méndez Mendoza ◽  
Rubén Huerta Crispín ◽  
Octavio Guerrero Andrade ◽  
...  
Keyword(s):  
Gene Expression ◽  
Germ Cell ◽  
Mrna Expression ◽  
Cell Apoptosis ◽  
Differential Sensitivity ◽  
Male Rats ◽  
Mrna Levels ◽  
Germ Cell Apoptosis ◽  
Expression Of Genes ◽  
Prepubertal Rats

Male germ-cell apoptosis occurs naturally and can be increased by exposure to drugs and toxic chemicals. Individuals may have different rates of apoptosis and are likely to also exhibit differential sensitivity to outside influences. Previously, we reported that p-chloroamphetamine (pCA), a substance that inhibits serotonin synthesis, induced germ-cell apoptosis in prepubertal male rats. Here, we identified prepubertal rats with naturally high or low rates of germ-cell apoptosis and evaluated gene expression in both groups. Bax and Shbg mRNA levels were higher in rats with high rates of germ-cell apoptosis. Rats were then treated with pCA and the neuro-hormonal response and gene expression were evaluated. Treatment with pCA induced a reduction in serotonin concentrations but levels of sex hormones and gonadotrophins were not changed. Rats with initially high rates of germ-cell apoptosis had even higher rates of germ-cell apoptosis after treatment with pCA. In rats with high rates of germ-cell apoptosis Bax mRNA expression remained high after treatment with pCA. On the basis of category, an inverse relationship between mRNA expression of Bax and Bcl2, Bax and AR and Bax and Hsd3b2 was found. Here we provide evidence that innate levels of germ-cell apoptosis could be explained by the level of mRNA expression of genes involved with apoptosis and spermatogenesis.

Gene regulation of ENaC subunits by serum- and glucocorticoid-inducible kinase-1

2005 ◽  
Vol 288 (3) ◽  
pp. F505-F512 ◽  
Author(s):  
Cary Boyd ◽  
Anikó Náray-Fejes-Tóth
Keyword(s):  
Gene Expression ◽  
Maximum Level ◽  
Dominant Negative ◽  
Mrna Levels ◽  
Loss Of Function ◽  
Delayed Effect ◽  
Subunit Mrna ◽  
Fold Induction ◽  
Free Media ◽  
First Time

Aldosterone is a key regulator of epithelial Na+ channels (ENaC) in renal cortical collecting ducts (CCD). The goal of this study was to examine whether serum- and glucocorticoid-inducible kinase-1 (SGK1), an aldosterone-induced gene, is vital to the delayed effect of aldosterone by increasing the gene expression of ENaC subunits. To test this hypothesis, we compared the levels of ENaC mRNA in mouse CCD cells that stably express either full-length (FL)-SGK1 or a kinase-dead dominant negative (K127M)-SGK1. Our results revealed that SGK1 regulates gene expression of ENaC, whether cells are maintained in steroid-free media or in the presence of corticosteroids (CS) and/or other growth factors. Under all conditions, the loss of function of SGK1 caused a significant decrease in the expression of α- and β-ENaC, but not γ-ENaC. Compared with cells expressing FL-SGK1, K127M-SGK1 decreased the expression of α- and β-subunit mRNA by ∼45 and ∼90%, respectively. Next, to determine whether SGK1 is one of the proteins mediating the induction of α-ENaC mRNA by CS, we compared steroid induction of α-ENaC in cells expressing K127M-SGK1 vs. FL-SGK1. The maximum level of α-ENaC mRNA levels following CS was significantly (∼45%) higher in FL-SGK1- vs. K127M-SGK1-expressing cells, although the fold-induction by CS was similar in both FL-SGK1- and K127M-SGK1-expressing cells. In summary, we report for the first time that SGK1 regulates transcription of ENaC subunits. We propose that the effect of SGK1 on ENaC transcription is mediated by the activation of unidentified transcription factors.

Uteroplacental insufficiency alters hepatic fatty acid-metabolizing enzymes in juvenile and adult rats

2001 ◽  
Vol 280 (1) ◽  
pp. R183-R190 ◽  
Author(s):  
Robert H. Lane ◽  
David E. Kelley ◽  
Elisa M. Gruetzmacher ◽  
Sherin U. Devaskar
Keyword(s):  
Gene Expression ◽  
Fatty Acid ◽  
Fatty Acid Metabolism ◽  
Acid Metabolism ◽  
Female Rats ◽  
Mrna Levels ◽  
Adult Rats ◽  
Serum Triglycerides ◽  
Hepatic Fatty Acid ◽  
Malonyl Coa

Multiple adult morbidities are associated with intrauterine growth retardation (IUGR) including dyslipidemia. We hypothesized that uteroplacental insufficiency and subsequent IUGR in the rat would lead to altered hepatic fatty acid metabolism. To test this hypothesis, we quantified hepatic mRNA levels of acetyl-CoA carboxylase (ACC), carnitine palmitoyltransferase (CPTI), the β-oxidation-trifunctional protein (HADH), fasting serum triglycerides, and hepatic malonyl-CoA levels at different ages in control and IUGR rats. Fetal gene expression of all three enzymes was decreased. Juvenile gene expression of CPTI and HADH continued to be decreased, whereas gene expression of ACC was increased. Serum triglycerides were unchanged. A sex-specific response was noted in the adult rats. In males, serum triglycerides, hepatic malonyl-CoA levels, and ACC mRNA levels were significantly increased, and CPTI and HADH mRNA levels were significantly decreased. In contrast, the female rats demonstrated no significant changes in these variables. These results suggest that uteroplacental insufficiency leads to altered hepatic fatty acid metabolism that may contribute to the adult dyslipidemia associated with low birth weight.

scholarly journals MiR-132 Regulates Rem Expression in Cardiomyocytes During Long-Term β-Adrenoceptor Agonism

2015 ◽  
Vol 36 (1) ◽  
pp. 141-154 ◽  
Author(s):  
Elba D. Carrillo ◽  
Raúl Sampieri ◽  
Ascención Hernández ◽  
María C. García ◽  
Jorge A. Sánchez
Keyword(s):  
Hek293 Cells ◽  
Luciferase Reporter ◽  
Protein Abundance ◽  
Mrna Levels ◽  
Luciferase Reporter Gene ◽  
Adult Rats ◽  
Subunit Mrna ◽  
Cav1.2 Channels ◽  
Polymerase Chain

Aims: To characterize the effects of long-term β-adrenergic receptor stimulation on Rem protein and mRNA expression in rat heart and possible involvement of miR-132. Methods: Adult rats were treated with isoproterenol (ISO, 150 µg.kg.h-1) for 2 d and Rem, miR-132, and α1c (the principal subunit of Cav1.2 channels) were measured at protein and mRNA levels with western blot and quantitative reverse transcriptase polymerase chain reaction (qRT-PCR) experiments, respectively. Ca2+ currents and intracellular Ca2+ signals were evaluated in isolated cardiomyocytes. Results: Systemic administration of ISO led to decreases in Rem protein and mRNA levels (down to 49%). Furthermore, levels of the microRNAs (miRs) miR-132 and miR-214 were upregulated 5- and 9-fold, respectively. Transfection of miR-132, but not miR-214, into HEK293 cells reduced the expression of a luciferase reporter gene controlled by a conserved 3´-untranslated region (UTR) of Rem by half. Chronic ISO administration also led to a 25% decrease in the amplitude of peak L-type Ca2+ currents, a 40% decrease in α1c subunit protein abundance at the membrane level, and a 60% decrease in expression of α1c channel subunit mRNA. Conclusions: These results suggest that Rem expression is down-regulated posttranscriptionally by miR-132 in response to long-term activation of β-adrenergic signaling, but this down-regulation does not produce a larger Ca2+ influx through Cav1.2 channels.

Effect of blockade of mGluR5 on stress hormone release and its gene expression in the adrenal gland

2014 ◽  
Vol 92 (8) ◽  
pp. 686-692 ◽  
Author(s):  
Michal Pokusa ◽  
Barbora Prokopova ◽  
Natasa Hlavacova ◽  
Aikaterini Makatsori ◽  
Daniela Jezova
Keyword(s):  
Gene Expression ◽  
Adrenal Gland ◽  
Metabotropic Glutamate Receptor ◽  
Glutamate Release ◽  
Catecholamine Release ◽  
Male Rats ◽  
Receptor Subtype ◽  
Mrna Levels ◽  
Hormone Release ◽  
Different Strains

The aim of this study was to verify the presence of metabotropic glutamate receptor subtype 5 (mGluR5) in the adrenal gland of male rats of 2 different strains, and to test the hypothesis that treatment with mGluR5 antagonist 2-methyl-6-(phenylethynyl)-pyridine (MPEP) affects hormone release and adrenal gene expression of mGluR5 under conditions of stress. The results clearly show the gene expression of mGluR5 in the adrenal gland in both the adrenal cortex and medulla. Treatment with the glutamate release inhibitor riluzole (4 mg·(kg body mass)–1·day–1 for 2 weeks) failed to modify mRNA levels of either the mGluR5 or NR1 subunit of the NMDA receptor in the adrenal glands, as measured by real-time PCR. Blockade of mGluR5 with MPEP (1 mg·kg–1 for 4 days) increased corticosterone but not catecholamine release during restraint stress (20 min). Treatment with MPEP had no effect on mRNA levels coding for steroidogenic factors StAR and SF-1, and decreased mGluR5 gene expression in the adrenal gland. In conclusion, mGluR5 is not likely to play a significant role in stress-induced catecholamine release. Pharmacological blockade of mGluR5 has a modest influence on the hypothalamic–pituitary–adrenocortical axis, as reflected in adrenal hypertrophy and increased corticosterone concentrations.

scholarly journals Gender and gonadal influences on ghrelin mRNA levels in rat stomach

2001 ◽  
pp. 687-690 ◽  
Author(s):  
O Gualillo ◽  
JE Caminos ◽  
M Kojima ◽  
K Kangawa ◽  
E Arvat ◽  
...  
Keyword(s):  
Mrna Expression ◽  
Gonadal Hormones ◽  
Female Rats ◽  
Male Rats ◽  
Mrna Levels ◽  
Rat Stomach ◽  
Adult Rats ◽  
Stable Level ◽  
Young Rats

OBJECTIVE: The recently isolated endogenous GH secretagogue, named ghrelin, is a gastric peptide of 28 amino acids with an n-octanoylation in the serine 3 that confers the biological activity to this factor. Ghrelin has been shown to directly stimulate GH release in vivo and in vitro and to be involved in the regulation of gastric acid secretion and motility. In the present work we have studied gender and gonadal dependency of ghrelin mRNA expression in rat stomach. DESIGN AND METHODS: We analysed ghrelin mRNA expression in rat stomach by Northern blot analysis. We also examined the effect of gonadal steroid deprivation on ghrelin mRNA expression. RESULTS AND CONCLUSIONS: The results obtained showed clearly that ghrelin gastric mRNA expression increased with age in young rats (up to 90 days old) but exhibited no significant sex difference at each age tested. Ghrelin mRNA levels were lowest at postnatal day 9, reaching a stable level of expression at day 40 in both female and male rats, although the increase in female rats appears much more gradual than that in males. Moreover, neither ovariectomy nor orchidectomy significantly modified ghrelin mRNA gastric levels in adult rats. In conclusion, these data indicate that ghrelin mRNA expression is associated with age and that a progressive increase is present from the perinatal period up to a stable level after puberty. Gonadal hormones did not alter ghrelin mRNA levels. Taken together, these data showed that ghrelin mRNA levels in young rats are age but not gender dependent, and are not influenced by gonadal steroids.

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