Effect of diet and ration on the relationship between plasma GH and IGF-1 concentrations in Arctic charr, Salvelinus alpinus (L.) (original) (raw)
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2015
The purpose of the study was to investigate whether dietary ration or diet composition in£uence the rela-tionship between plasma growth hormone (GH) and insulin-like growth factor-1 (IGF-1) in Arctic charr (Salvelinus alpinus L.). The pattern of changes in plas-ma GH and IGF-1 concentrations was examined in ¢sh fed at di¡erent ration levels (0%, 0.35 % and 0.70%BWday1) for 5 weeks, and in ¢sh fed diets containing di¡erent lipid:crude protein (LCP) ratios. Ration level signi¢cantly a¡ected plasma GH and IGF-1 concentrations; at 5 weeks the levels of both hormones in the food-deprived group were signi¢-cantly lower than in ¢sh fed the 0.70%BWday1 ra-tion. Also, plasma IGF-1 levels in ¢sh of each ration
Aquaculture, 2000
In this study, the effect of the ratio of lipid to carbohydrate non-protein energy sources on the Ž. Ž. growth and circulating insulin-like growth factor IGF-I and triiodothyronine T3 levels of juvenile barramundi was examined using a 2 = 3 factorial design experiment. Isonitrogenous diets Ž. Ž y1. 50% crude protein were formulated at two gross energy levels 18 and 21 MJ kg and three Ž. ratios of lipid to carbohydrate non-protein energy 60:40, 70:30 and 80:20. Animals were held in Ž. 70 l aquaria receiving recirculated seawater 28 ‰ at 258C. Animals were fed daily to satiety for 70 days. T3 and IGF-I levels were measured using radioimmunoassays validated for use for this species. Lipid and carbohydrate energy were supplied as marine fish oil and gelatinized corn starch, respectively. Gelatinized starch was generally well utilized by juvenile barramundi, though its utilization may be limited above the 17% inclusion level. Increases in dietary energy resulted in higher growth rates and feed conversion as well as elevated protein and lipid gain. A significant protein sparing effect of both carbohydrate and lipid was demonstrated for juvenile barramundi. Circulating levels of T3 and IGF-I responded to dietary treatment, however they did not relate directly to any measured growth parameter. The relationships between nutrition, growth and the underlying mechanisms controlling growth are discussed.
Analysis of the effect of feeding regimen on GH/IGF axis in channel catfish (Ictalurus punctatus)
2012
Channel catfish (Ictalurus punctatus) are the most widely farmed aquatic animal in the United States. Assessing the effect of feeding regimens on their overall growth requires grow-out trials and a subsequent inefficient use of time and money. The growth hormone (GH)/insulin-like growth factor-1 (IGF-1) axis regulates growth based upon environmental factors such as feed intake in many teleost fish species. In order to increase the efficiency of aquaculture, the components of the GH/IGF-1 axis might be used as endocrine biomarkers to evaluate instantaneous growth rate. The goal of this study was to better understand the effects of feeding regimen on the regulation of growth in channel catfish. Accelerated growth during re-feeding periods after fasting is of particular interest. These periods, termed compensatory growth (CG) periods, have been observed in several teleost fishes. To study this, mRNA expression of GH/IGF-1 axis components was examined in the liver, skeletal muscle and pituitary of channel catfish during two weeks of fasting and one week of re-feeding with a control group of animals fed daily. In addition, hepatosomatic index (HSI) and condition factor (CF) were calculated for each fish. CF data suggests CG after only a week of re-feeding. Fasting induced a significant decrease (P<0.05) in HSI, which returned to normal after re-feeding. Fasting induced a significant increase in muscular ghr-1 (P<0.01) and a significant decrease in muscular igf-1 (P<0.001). Re-feeding induced a significant increase in hepatic igf-1 (P<0.001), igfbp-5a (P<0.01), igfr-1a (P<0.001), and ghr-1 (P<0.01) and in muscular igf-2 (P<0.01), igfbp-1 (P<0.001), igfbp-2 (P<0.01), igfbp-5a (P<0.05), and igfr-1a (P<0.05). Results indicate that the GH/IGF-1 axis is highly sensitive to re-feeding in channel catfish and that CG can be induced.
Animals, 2019
The objective of this study was to investigate the effects of different dietary energy levels on serum concentrations of growth hormone (GH) and insulin-like growth factor 1 (IGF-1), as well as gene expression of their associated binding proteins and receptors in yak. Fifteen adult male yaks with BW of 276.1 ± 3.5 kg were allotted in three dietary groups and were fed with low (LE), medium (ME), and high energy (HE) level diet having different NEg of 5.5 MJ/kg, 6.2 MJ/kg, 6.9 MJ/kg, respectively. The effects of these treatments on ADG, BW, ADFI, and feed conversion ratio were significant (p < 0.05) throughout the experimental period. Serum GH concentration decreased (p < 0.05) with an increase in dietary energy level on d 30 and d 60. While IGF-1 concentration was higher (p < 0.05) in ME group, as compared to LE and HE groups on d 60. The expression level of growth hormone receptor (GHR) was decreased (p < 0.001) and IGF-1 was increased with the increase in the dietary en...
Growth hormone axis as marker of nutritional status and growth performance in fish
Aquaculture, 1999
The endocrine control of growth and metabolism is interrelated and many of the endocrine factors involved in the regulation of lipid and protein metabolism are also involved in nutrient utilization, immune system function and somatic growth. All these processes are impaired in catabolic states induced by fasting, protein deprivation and chronic liver diseases as a response to the consequential changes in the endocrine system. In this regard, it must be noted that concentrations of circulating metabolites may be quite different depending on the catabolic state. However, in all the metabolic disorders that shared an increased catabolismranabolism balance, plasma insulin levels are depressed, whereas those of GH are elevated. This hypersomatotropism, linked to growth retardation, is accompanied by a reduction of plasma IGF-I concentration, which reflects some refractoriness of liver to the anabolic action of GH. Changes in GH availability and liver GH-responsiveness can also be established as a function of age, fish species, and environ-Ž . mental factors photoperiod and temperature . In the present work, the regulation and mode of GH action is discussed in order to provide a useful tool to assess the nutritional status and growth performance of cultured fish. q 0044-8486r99r$ -see front matter q 1999 Elsevier Science B.V. All rights reserved.
AFRICAN JOURNAL OF BIOTECHNOLOGY
This study aimed to show the difference in compensatory growth (CG) with different starvation and feeding periods replications, depending on the IGF-I hormone level in the blood. There were 4 treatments in 3 replications. Other indexes like food coefficient ratio (FCR), specific growth rate (SGR) and daily food intake were also examined during the experiment. Fish were fed twice a day ad libitum as follows during the 65 days. Treatment A (TA): control treatment, continues feeding. Treatment B (TB): 4 weeks of starvation and 5 weeks of re-feeding. Treatment C (TC): 3 weeks of starvation and 5 weeks of re-feeding. Treatment D (TD): 2 weeks of starvation and 5 weeks of re-feeding. Each tank contained 23 fishes in each unit with an initial mean weight (SD) of 47.19 ± 0.42 (g). Blood was sampled in IGF-I hormone concentration at the beginning of the experiment, at the end of the starvation period and every 12 days in re-feeding periods. There was no significant difference between the tre...
Aquaculture Research, 2002
Sexually immature Arctic charr, Salvelinus alpinus (Linnaeus), were fed one of five isoenergetic practical diets of differing lipid:protein ratios (0.98, 0.67, 0.41, 0.26, 0.19) for an 84-day period to examine the influence of diet composition on growth, and growth hormone (GH) and thyroid hormone physiology. All five diets supported growth at approximately the same rate, but the diet with a lipid: protein ratio of 0.98 had the lowest weight gain and highest food conversion ratios. A GH enzymelinked immunosorbent assay (ELISA), developed for use with oncorhynchid fishes, was validated for use with Arctic charr. Plasma GH concentrations were significantly higher in fish fed the diet with a lipid:protein ratio of 0.98, and there were significant direct and inverse correlations between plasma GH levels and dietary lipid and protein content respectively. There were no significant differences in pre-and post-prandial plasma GH concentrations for any group. There were significant post-prandial elevations of plasma triiodothyronine (T 3 ) and thyroxine (T 4 ) for fish fed the lower lipid:protein ratio diets, but there were no differences related to the diets. The results are discussed in terms of GH as a factor in the regulation of lipid and protein homeostasis in fishes.
Fish Physiology and Biochemistry, 2014
Cichlasoma dimerus is a social cichlid fish capable of growing at high rates under laboratory conditions, but knowledge on somatic growth regulation is still unclear. Growth hormone (GH)/insulin-like growth factor I (IGF-I) axis is the key regulator of somatic growth in vertebrates. Two types of growth hormone receptors have been described in teleost fish, named GH receptor type 1 (GHR1) and type 2 (GHR2). In addition, isoforms of these receptors lacking part of the intracellular region have been described. The aim of this study was to evaluate the somatic growth, liver histology and changes in the GH/IGF-I axis after 4 weeks of food deprivation in C. dimerus. Four-week fasted fish showed reductions in specific growth rates in body weight (p \ 0.001) and standard length (p \ 0.001). Additionally, the hepatosomatic index (p \ 0.001) and hepatocyte area (p \ 0.001) decreased in fasted fish, while no changes in glucose levels were detected in plasma. The starvation protocol failed to induce changes in GH mRNA levels in the pituitary and IGF-I mRNA levels in liver. In contrast, IGF-I mRNA levels in muscle decreased in fasted fish (p = 0.002). On the other hand, GHR2 (detected with primer sets designed over the extracellular and intracellular region) was upregulated by starvation both in liver and muscle (p \ 0.05), while GHR1 remained unchanged. These results show that a fasting period reduced somatic growth both in length and body weight concomitantly with alterations on liver and muscle GHR2 and muscle IGF-I mRNA expression.
Fish Physiology and Biochemistry, 1993
Un dosage des somatomédines (IGF) plasmatiques de téléostéens a été mise au point, en utilisant une protéine du sérum de truite qui lie spécifiquement les IGF humains (Niu and Le Bail 1993). Pour éliminer les risques d'interférence dues aux protéines de liaison (IGF-BP), l'activité IGF des différents échantillons a été extraite à l'aide de SP Sephadex C-25 en condition acide. La contamination en IGF-BP de ces extraits est estimée à 5% par dosage de la liaison et n'est pas détectable en western ligand blot. L'IGF-I humain a été utilisée comme standard et comme traceur. La sensibilité du dosage est de 0.15–0.40 ng/ml (ED90) et l'ED50 varie entre 1 et 3 ng/ml. L'IGF-II humain est reconnue partiellement mais aucune réaction croisée n'est observée avec de l'insuline de différentes espèces ni avec les autres hormones testées. Les courbes d'inhibition obtenues avec les sera de mammifères et de téléostéens sont parallèles à la courbe standard. Ces résultats montrent que le dosage par protéine de liaison est capable de quantifier une activité de type IGF dans le sérum des téléostéen, et que le site de liaison des IGF est resté bien conservé au cours de l'évolution des vertébrés. En utilisant ce dosage, nous avons mesuré l'activité IGF et les niveaux d'hormone de croissance (GH) dans des plasmas de jeunes truites arc-en-ciel abattues toutes les heures et demie durant 24h. Les profils nycthémér-aux des deux hormones, qui sont de type pulsatile, apparaissent similaires. Une corrélation significative est observée entre les niveaux de GH et les activités IGF circulant une heure et demie plus tard. Des observations analogues ont été faites chez des truites adultes cathétérisées. Cependant, les niveaux plasmatiques de GH sont très différents d'un animal à l'autre, alors que les variations de l'activité IGF sont moins prononcées. Dans une troisième expérience, des truites ont été réparties en trois groupes: un groupe contrôle, un groupe traité avec de la GH bovine et un groupe soumis à un jeûne prolongé. Chez les animaux à jeun, les niveaux de GH augmentent alors que les activités IGF diminuent. Chez les animaux injectés avec de la GH, les activités IGF sont significativement plus élevées que chez les animaux témoins. Ces résultats suggèrent que, comme chez les mammifères, la sécrétion des IGF plasmatiques est contrôlée par les niveaux circulants de GH et que les variations de la réceptivité tissulaire à la GH dépendent de l'état nutritionnel des animaux. Using rainbow trout plasma protein (IGF-BP) which specifically binds human insulin-like growth factor (IGF) (Niu and Le Bail 1993), we have developed an assay to measure plasma IGF-like levels in different teleost species. Before the assay and to prevent interference by IGF-BP, IGF-like was extracted from all samples, using SP Sephadex C-25 in acidic conditions. After this treatment, contamination of the IGF fraction by IGF-BP which was estimated by binding assay, was approximately 5%, and was not detectable by western ligand blot. Human IGF-I was used as standard and labelled hormone. Sensitivity of the assay was 0.15–0.40 ng/ml (ED90) and ED50 was 1–3 ng/ml. hIGF-II crossreaction was partial and no significant displacement was observed with Insulin from different species or with other hormones. Inhibition curves were obtained with plasma IGF fractions (but not with tissue extracts) from teleost and mammals and are parallel to the standard curve. These results suggest that the protein binding assay can quantify an IGF-like factor in the plasma of teleost and that the binding sites of IGF are well conserved during vertebrate evolution. Using this IGF binding assay, IGF-like was measured in parallel with growth hormone (GH) in plasma from young rainbow trout killed every 1.5h throughout one day. The daily profiles for both hormones, which appear pulsatile, are similar. A significant correlation was observed between GH levels and IGF-like levels with a 1.5h delay. Analogous observations were obtained in individual catheterized adult rainbow trout. Although plasma GH levels differ greatly between fish, less variability is found with IGF-like. In a third experiment, rainbow trout were starved or submitted to bovine GH treatment for four weeks. Starved fish, in which plasma GH levels increased, had plasma IGF-like level significantly lower than in fed fish. In bGH injected fish, plasma IGF-like level was significantly higher than in non-injected fish. These results suggest that, as in mammals, IGF-like secretion depends on plasma GH level and could be modulated by the nutritional status of fish.