Comparative effects of food restriction, fasting, diabetes and thyroidectomy on growth hormone and thyrotropin gene expression in the rat pituitary

1995 ◽  
Vol 133 (1) ◽  
pp. 110-116 ◽  
Author(s):  
Manuela Rodriguez ◽  
Felipe Rodriguez ◽  
Trinidad Jolin ◽  
Pilar Santisteban
Keyword(s):  
Gene Expression ◽  
Growth Hormone ◽  
Food Restriction ◽  
Blot Hybridization ◽  
Northern Blot Hybridization ◽  
Mrna Levels ◽  
Restricted Feeding ◽  
Rat Pituitary ◽  
Ad Libitum ◽  
Ad Libitum Intake

Rodriguez M, Rodriguez F, Jolin T, Santisteban P. Comparative effects of food restriction, fasting, diabetes and thyroidectomy on growth hormone and thyrotropin gene expression in the rat pituitary. Eur J Endocrinol 1995;133:110–6. ISSN 0804–4643 To examine the molecular basis for the decreased pituitary growth hormone (GH) and thyrotropin (TSH) content during restricted feeding, fasting and diabetes, we measured steady-state levels of mRNA for TSH-α TSH-β and GH in the pituitary from normal rats either fed ad libitum (C), limited to 75%, 50% and 25% (FR75, FR50, FR25, respectively) of ad libitum intake, or deprived of food for 2 and 4 days (F2 and F4, respectively), and also in streptozotocin-diabetic (D) and D insulin-treated animals. The results from these experimental groups were compared with those in thyroidectomized (Tx) rats. Pituitary mRNA was quantified by Northern blot hybridization with cDNA probes specific for rat TSH-α, TSH-β and GH. Although changes in the pituitary GH mRNA during restricted feeding, fasting and diabetes were similar qualitatively to those induced by hypothyroidism, GH mRNA levels in Tx rats (> 10% of C values) were less than in the other experimental groups (p < 0.001). Pituitaries from FR50, FR25 and D rats also contained less GH mRNA than F2 and F4 animals (p < 0.05). Thyroidectomy resulted in a marked increase in both TSH-β and TSH-α mRNAs, the changes in TSH-β mRNA being greater than those in TSH-α mRNA. In contrast, FR50, FR2 5, F2, F4 and D rats exhibited a decrease in pituitary TSH-β mRNA (60%, 50%, 35%, 36% and 33%, respectively, of C values; p < 0.01–0.05) and in TSH-α mRNA levels (81%, 64%, 46%, 43% and 36%, respectively, of normal values; p < 0.02–0.05), TSH-β mRNA showing the greater changes. However, pituitaries from F2, F4 and D rats contained less TSH-β and TSH-α mRNA levels than FR50 and FR25 animals (p < 0.05). Insulin therapy partially restored the changes in mRNA for GH, TSH-β and TSH-α observed in D rats. In addition, the pituitary nuclear triiodothyronine in Tx, FR50, FR25, F2, F4 and D rats was reduced to 19%, 73%, 52%, 76%, 51% and 41%, respectively of C values (p < 0.05–0.001). These data suggest that GH, TSH-α and TSH-β gene expression are modulated by metabolic and/or endocrine changes accompanying restricted feeding, fasting and diabetes. P Santisteban, Instituto de Investigaciones Biomédicas, CSIC, Arturo Duperier 4, 28029 Madrid, Spain

scholarly journals Chronic food-restriction alters the expression of somatostatin and growth hormone-releasing hormone in the ovariectomised ewe

2001 ◽  
Vol 170 (1) ◽  
pp. R1-R5 ◽  
Author(s):  
BA Henry ◽  
A Rao ◽  
AJ Tilbrook ◽  
IJ Clarke
Keyword(s):  
Gene Expression ◽  
Growth Hormone ◽  
Food Restriction ◽  
In Situ Hybridisation ◽  
Hypothalamic Nucleus ◽  
Mrna Levels ◽  
Growth Hormone Releasing Hormone ◽  
Releasing Hormone ◽  
Periventricular Nucleus ◽  
Chronic Food Restriction

Changes in the secretion of GH induced by long-term alterations in nutritional status are thought to result from alterations in somatostatin (SRIF) and growth hormone-releasing hormone (GHRH) at the level of the hypothalamus. To date however, the effect of nutrition on the gene expression of SRIF and GHRH in a species where GH secretion is increased by food restriction, as is the case for the sheep and human, remains unknown. We determined the effect of under-nutrition on the expression of SRIF and GHRH in the hypothalamus of sheep. Ovariectomised ewes were randomly divided into two groups and either fed an ad lib diet (n=6) or a restricted diet of 500 g lucerne chaff per day (food-restricted; n=5) for 7 months. In situ hybridisation was used to study hypothalamic gene expression for GHRH, SRIF and galanin (GAL). The food-restricted animals had elevated plasma concentrations of GH; this was associated with an increase in GHRH mRNA levels in the arcuate nucleus (ARC) and reduced SRIF in the rostral periventricular nucleus and ventromedial hypothalamic nucleus. The level of gene expression of GAL in the ARC and SRIF in the caudal periventricular nucleus was similar in ad lib and food-restricted animals. In conclusion, the effect of chronic food-restriction on the secretion of GH reflects increased GHRH and reduced SRIF synthesis in the hypothalamus.

Stimulation of angiotensinogen mRNA levels in rat pituitary by estradiol

1992 ◽  
Vol 263 (2) ◽  
pp. E355-E361 ◽  
Author(s):  
D. P. Healy ◽  
M. Q. Ye ◽  
L. X. Yuan ◽  
B. S. Schachter
Keyword(s):  
Blot Hybridization ◽  
Male Rats ◽  
Normal Male ◽  
Northern Blot Hybridization ◽  
Mrna Levels ◽  
Ang Ii ◽  
Local Synthesis ◽  
Angiotensinogen Gene ◽  
Ovx Rats ◽  
Rat Pituitary

Angiotensin II (ANG II) is a putative paracrine hormone in the anterior pituitary. Angiotensinogen mRNA, however, is not detectable by Northern blot hybridization, suggesting that ANG II may not be synthesized within the pituitary. An alternative explanation may be that angiotensinogen gene activity is low under normal conditions, with angiotensinogen mRNA being below the level of detection. Utilizing a sensitive solution hybridization method, we sought to determine whether angiotensinogen mRNA could be detected in pituitaries from normal male rats or ovariectomized (OVX) rats treated with estradiol (E2) for 4 days. Very low levels of angiotensinogen mRNA were detected from male or OVX rat pituitaries, but E2 treatment resulted in a marked dose-dependent increase in pituitary angiotensinogen mRNA levels. Levels of angiotensinogen within the pituitary were not significantly different after the E2 treatment. Angiotensinogen mRNA levels in liver and brain were much higher than in the pituitary but were not altered significantly by the chronic E2 treatment. These results are consistent with the local synthesis of angiotensinogen in the pituitary and further suggest that pituitary angiotensinogen gene transcription is regulated by estrogen.

scholarly journals The influence of food restriction versus ad libitum feeding of chow and purified diets on variation in body weight, growth and physiology of female Wistar rats

2012 ◽  
Vol 46 (2) ◽  
pp. 101-107 ◽  
Author(s):  
M Moraal ◽  
P P A M Leenaars ◽  
H Arnts ◽  
K Smeets ◽  
B S Savenije ◽  
...  
Keyword(s):  
Body Weight ◽  
Food Restriction ◽  
Wistar Rats ◽  
Statistical Significance ◽  
Blood Parameters ◽  
Calorie Intake ◽  
Restricted Feeding ◽  
Organ Weights ◽  
Female Wistar Rats ◽  
Ad Libitum

Ad libitum (AL) supply of standard chow is the feeding method most often used for rodents in animal experiments. However, AL feeding is known to result in a shorter lifespan and decreased health as compared with restricted feeding. Restricted feeding and thus limiting calorie intake prevents many health problems, increases lifespan and can also increase group uniformity. All this leads to a reduced number of animals needed. So-called standard chows are known to be prone to variation in composition. Synthetic foods have a more standard composition, contributing to group uniformity which, like diet reduction, may decrease the number of animals necessary to obtain statistical significance. In this study, we compared the effects of AL versus restricted feeding (25% reduction in food intake) on standard chow versus synthetic food of three different suppliers on body weight (BW), growth, several blood parameters and organ weights in growing female Wistar rats over a period of 61 days. Diet restriction led to a decreased growth and significantly reduced variation in BW and growth as compared with AL feeding. AL feeding on synthetic diets caused a significantly higher BW gain than on chow diets. Due to experimental design, this same effect occurred on food restriction. Blood parameters and organ weights were affected neither by diet type nor by amount. Incidentally, variations were significantly reduced on food restriction versus AL, and on synthetic diets versus chow diets. This study demonstrates that food restriction versus AL feeding leads to a significantly reduced variation in BW and growth, thereby indicating the potential for reduction when applying this feeding schedule.

scholarly journals Changes in collagenase and collagen gene expression after induction of aortocaval fistula in rats

2001 ◽  
Vol 281 (1) ◽  
pp. H207-H214 ◽  
Author(s):  
S. M. Dolgilevich ◽  
F. M. Siri ◽  
S. A. Atlas ◽  
C. Eng
Keyword(s):  
Gene Expression ◽  
Blot Hybridization ◽  
Northern Blot Hybridization ◽  
Collagen Gene ◽  
Aortocaval Fistula ◽  
Molecular Alterations ◽  
Collagen Gene Expression ◽  
Matrix Metalloproteinase 1 ◽  
Time Courses ◽  
Collagenase Gene

Progressive ventricular dilatation commonly accompanies the transition to overt failure in chronically overloaded hearts; however, only recently have studies begun to elucidate underlying molecular alterations. In particular, the potential role of altered myocardial expression of the procollagenase gene in this process has not previously been examined. Biventricular hypertrophy and dilatation were produced in rats by creating an abdominal aortocaval fistula. The time courses of changes in expression of collagen I and III genes and of the procollagenase gene (matrix metalloproteinase-1, MMP-1) were assessed by Northern blot hybridization. Expression of all three genes increased promptly; however, collagenase gene expression peaked much earlier (8 h) than did expression of either of the collagen genes (7 days), and all returned to baseline levels by 45 days. These data corroborate earlier reports of increased collagen gene expression in this model, but more importantly, they provide the first evidence of concurrent activation of collagenase gene expression, suggesting that enhancement of collagen degradation may be a prerequisite for structural cardiac dilatation.

The effect of restricted feeding on growth hormone (GH) secretory patterns in genetically lean and fat wether lambs

2000 ◽  
Vol 70 (3) ◽  
pp. 425-433 ◽  
Author(s):  
S. M. Francis ◽  
R. P. Littlejohn ◽  
S. K. Stuart ◽  
B. A. Veenvliet ◽  
J. M. Suttie
Keyword(s):  
Growth Hormone ◽  
Treatment Group ◽  
Developmental Change ◽  
Plasma Concentrations ◽  
Live Weight ◽  
Carcass Composition ◽  
Restricted Feeding ◽  
Ad Libitum ◽  
Plasma Gh ◽  
And Control

AbstractThe aim of this work was to determine whether developmental changes in growth hormone (GH) secretory patterns and carcass composition were influenced by nutrition and genotype in sheep. Four-month-old wether lambs from lean (low backfat), fat (high backfat) and control selection lines were nutritionally restricted to maintain a 28 kg live weight or given food ad libitum for 24 weeks. Plasma concentrations of GH and insulin-like growth factor 1 (IGF-1) were measured at predetermined times and carcass composition of the animals determined at the end of the trial.From week 3 on, restrictions in dry matter (DM) intake were observed as the ad libitum treatment group had a significantly greater intake than the restricted treatment group (7·70 v. 5·80 kg DM per week, s.e.d. = 0·81). Differences in live weight between the feeding treatments were significant (P < 0·05) at week 9. The restricted feeding regime was associated with significant reductions in plasma levels of IGF-1 but had no effect (P > 0·05) on carcass weight-adjusted carcass fat proportion at the close of the trial. The effect of food restriction on GH secretory patterns was variable. Although there was initially a suppression in mean plasma GH, there was subsequently significantly higher mean plasma GH in the restricted feeding treatment. Periodogram analysis indicated that both the absolute levels of GH and the GH secretory pattern were altered by restricted feeding. In all animals, mean and basal GH concentrations, as well as the frequency and amplitude of pulses, declined from February to March and then increased from May to July (P < 0·001).DM intake and live weight did not differ (P > 0·05) between genotypes, however the fat genotype had greater carcass fatness than lean or control genotypes (P < 0·01). There were no consistent differences between genotypes in plasma IGF-1 concentrations. In the ad libitum treatment, the lean and control genotypes had higher plasma GH levels than the f at genotype but the pattern of GH release did not vary. Under restricted feeding, both the pattern and the level of plasma GH varied between genotypes.It is concluded that the developmental change in GH secretory patterns is affected by nutrition but not in a consistent manner. Although restricted feeding resulted in higher mean plasma GH concentrations later in the trial, this did not result in a change in carcass composition. The biological cues which lead to increased fat deposition in older lambs need further study but plasma GH levels may not he an important mechanism in this process.

Effect of residual feed intake phenotype–nutritional treatment interaction on the growth performance, plasma metabolic variables and somatotropic axis gene expression of growing ewes

2016 ◽  
Vol 56 (10) ◽  
pp. 1593 ◽  
Author(s):  
H. T. Nie ◽  
Z. Y. Wang ◽  
S. Lan ◽  
H. Zhang ◽  
Y. J. Wan ◽  
...  
Keyword(s):  
Gene Expression ◽  
Growth Hormone ◽  
Growth Performance ◽  
Feed Intake ◽  
Mrna Abundance ◽  
Feed Restriction ◽  
Somatotropic Axis ◽  
Nutritional Treatment ◽  
Treatment Interaction ◽  
Ad Libitum

This study aimed to evaluate the effect of residual feed intake (RFI) phenotype and nutritional treatment interaction on the growth performance, plasma variables and gene expression levels within the somatotropic axis. Growing ewes [n = 52, initial bodyweight (BW) = 17.5 ± 0.5 kg, 2 months of age] were offered ad libitum access to diets for 63 days and ranked based on RFI phenotype. Thirty ewes with the highest and lowest RFI values were selected and randomly assigned to three nutritional treatments based on dry matter intake (DMI), which are ad libitum (AL), low restriction (LR) and high restriction (HR) groups, respectively. Each nutritional treatment group included ewes with high (n = 5) and low RFI (n = 5) values. During nutritional treatment (from Day 64 to Day 138), plasma samples were obtained to measure metabolite and hormone concentrations. Tissues of the hypothalamus, pituitary, liver, and Longissimus dorsi muscle (LM) were harvested at the end of the experiment (Day 138) to measure the gene expression level within the somatotropic axis. Muscle growth hormone receptor mRNA abundance of low RFI ewes tended to be greater (P = 0.09) under AL feeding, but this difference was abolished by underfeeding (P > 0.10). Low RFI ewes under HR treatment showed slightly greater growth performance, which was accompanied with lower pituitary somatostain receptor 2 mRNA abundance (P < 0.05), plasma non-esterified fatty acid concentration (P < 0.05), and greater concentration of triglyceride (P < 0.05), compared with ewes classified as high RFI group. Our results suggested that ewes categorised as low RFI showed higher resistance to the condition of high feed restriction, which might be attributed to less intensity of fat mobilisation under negative energy balance. The mechanism underlying resistance to such feed restriction was presumably through action of somatostain receptor 2 and was potentially mediated by inhibitory effects of somatostatin on growth hormone release but not basal growth hormone secretion.

scholarly journals Effect of the GH secretagogue L-163,255 and restricted feeding time on GH pulsatility in the rat

2002 ◽  
pp. 143-148 ◽  
Author(s):  
AN Moulas ◽  
JD Veldhuis ◽  
JC Chan ◽  
Keyword(s):  
Growth Hormone ◽  
Oral Administration ◽  
Feeding Time ◽  
Restricted Feeding ◽  
Growth Hormone Secretagogue ◽  
Deconvolution Analysis ◽  
Blood Samples ◽  
Pulsatile Release ◽  
Before And After ◽  
Ad Libitum

OBJECTIVE: To determine the effect of repeated treatments with the growth hormone secretagogue (GHS) L-163,255 on the pulsatile release of GH when administered in meal-fed rats before and after feeding. DESIGN: The first group of rats (AL, n=6) had food available ad libitum. The second (restricted, R, n=6), third (GHSB, n=6), and fourth (GHSA, n=6) groups were fed from 1100 to 1400 h. Groups GHSB and GHSA were given GHS by gavage, 3.0 mg/kg L-163,255, at 1000 h (before feeding, B) and at 1500 h (after feeding, A) respectively. Three weeks after the initiation of the treatment, blood samples were collected at 10-min intervals over 6 h, and GH levels were determined. RESULTS: In group R, the concentrations of GH were higher before feeding (17.6+/-2.4 ng/ml) than during feeding (11.2+/-1.2 ng/ml), P<0.05. The average concentrations of the peak in response to GHS were higher when GHS was administered before (121.70+/-33.68 ng/ml) than after (49.67+/-17.87 ng/ml) feeding. The mass of GH, as calculated by deconvolution analysis was also higher in the GHSB group than in the GHSA group (251.6+/-64.1 ng/ml per min vs 85.3+/-22.9 ng/ml per min respectively, P<0.05). CONCLUSION: L-163,255 is effective in inducing GH release after repeated oral administration in rats. The effectiveness is greater when GHS is administered before rather than after feeding in meal-fed animals.

Effects of Morphine and Naloxone on Prolactin and Growth Hormone Gene Expression in the Male Rat Pituitary Gland

1993 ◽  
Vol 5 (5) ◽  
pp. 553-556 ◽  
Author(s):  
Pablo-Manuel Dobado-Berrios ◽  
Songuyn Li ◽  
Ester Garcia Yebenes ◽  
Georges Pelletier
Keyword(s):  
Gene Expression ◽  
Growth Hormone ◽  
Pituitary Gland ◽  
Male Rat ◽  
Growth Hormone Gene ◽  
Rat Pituitary

scholarly journals Western-diet consumption induces alteration of barrier function mechanisms in the ileum that correlates with metabolic endotoxemia in rats

2017 ◽  
Vol 313 (2) ◽  
pp. E107-E120 ◽  
Author(s):  
Mathilde Guerville ◽  
Anaïs Leroy ◽  
Annaëlle Sinquin ◽  
Fabienne Laugerette ◽  
Marie-Caroline Michalski ◽  
...  
Keyword(s):  
Gene Expression ◽  
Elevated Serum ◽  
Caloric Intake ◽  
Western Diet ◽  
Chow Diet ◽  
Low Grade ◽  
Mrna Levels ◽  
Intestinal Alkaline Phosphatase ◽  
Ad Libitum ◽  
Metabolic Endotoxemia

Obesity and its related disorders have been associated with the presence in the blood of gut bacteria-derived lipopolysaccharides (LPS). However, the factors underlying this low-grade elevation in plasma LPS, so-called metabolic endotoxemia, are not fully elucidated. We aimed to investigate the effects of Western diet (WD) feeding on intestinal and hepatic LPS handling mechanisms in a rat model of diet-induced obesity (DIO). Rats were fed either a standard chow diet (C) or a Western Diet (WD, 45% fat) for 6 wk. They were either fed ad libitum or pair-fed to match the caloric intake of C rats for the first week, then fed ad libitum for the remaining 5 wk. Six-week WD feeding led to a mild obese phenotype with increased adiposity and elevated serum LPS-binding protein (LBP) levels relative to C rats, irrespective of initial energy intake. Serum LPS was not different between dietary groups but exhibited strong variability. Disrupted ileal mucus secretion and decreased ileal Reg3-γ and -β gene expression along with high ileal permeability to LPS were observed in WD compared with C-fed rats. Ileal and cecal intestinal alkaline phosphatase (IAP) activity as well as Verrucomicrobia and Bifidobacterium cecal levels were increased in WD-fed rats compared with C-fed rats. WD consumption did not impact mRNA levels of LPS-handling hepatic enzymes. Correlation analysis revealed that ileal passage of LPS, IAP activity, Proteobacteria levels and hepatic aoah gene expression correlated with serum LPS and LBP, suggesting that ileal mucosal defense impairment induced by WD feeding contribute to metabolic endotoxemia.

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