Gut glucose metabolism in rainbow trout: implications in glucose homeostasis and glucosensing capacity

2010 ◽  
Vol 299 (1) ◽  
pp. R19-R32 ◽  
Author(s):  
Sergio Polakof ◽  
Rosa Álvarez ◽  
José L. Soengas
Keyword(s):  
Rainbow Trout ◽  
Amino Acid ◽  
Glucose Metabolism ◽  
Glucose Homeostasis ◽  
Oral Glucose ◽  
Mrna Levels ◽  
Surprising Result ◽  
In Vivo Experiments

The main objective of the present study was to evaluate the relative contribution of the intestine to glucose homeostasis in rainbow trout. In a first set of in vivo experiments trout were subjected to oral glucose treatments alone or in combination with insulin injections to assess changes in glucose-related enzymes activities, metabolite levels, and mRNA levels. Rainbow trout gut displays an important glucose metabolism that includes the ability to store glucose as glycogen (mostly in the muscle layers) and a large capacity to oxidize glucose. This constitutes a surprising result for a carnivorous fish. In a second set of in vivo experiments, trout received an oral amino acid solution alone or in combination with insulin injection to determine whether other factors besides fasting could regulate gluconeogenesis in intestine. The results confirm the absence of regulation of gluconeogenesis in trout gut, which does not respond to hormones, glucose, lactate, or amino acid changes, either in vivo or in vitro. We also fully characterized gut glucose metabolism in vitro. We observed that a large amount of glucose is oxidized to lactate, supporting the importance of glucose in gut metabolism. Moreover, we corroborated the minor actions of insulin in trout gut, whereas other hormones such as glucagon-like peptide-1 and C-peptide appear to be major hormonal regulators of glucose metabolism in fish gut. Finally, we obtained the first evidence for the existence of a glucosensing mechanism in the midgut of this carnivorous species.

Sheep antiluteolytic interferon: cDNA sequence and analysis of mRNA levels

1989 ◽  
Vol 2 (1) ◽  
pp. 65-70 ◽  
Author(s):  
H.J. Stewart ◽  
S.H.E. McCann ◽  
A.J. Northrop ◽  
G.E. Lamming ◽  
A.P.F. Flint
Keyword(s):  
Amino Acid ◽  
Northern Blotting ◽  
In Vitro Translation ◽  
Major Constituent ◽  
Interferon Α ◽  
Mrna Levels ◽  
Blastocyst Development ◽  
Cdna Sequences

ABSTRACT A cloned cDNA has been isolated by probing a sheep blastocyst cDNA library using a synthetic oligonucleotide representing the N-terminal amino acid sequence of the antiluteolytic protein, ovine trophoblast protein-1. Sequence analysis of the cDNA confirms the 70% homology between the antiluteolysin and the interferon-α family of proteins; however, the sequence reported here differs at several points from previously reported amino acid and cDNA sequences for the antiluteolysin. In-vitro translation of day-16 poly(A)+ RNA indicated that antiluteolysin mRNA is a major constituent of total mRNA at this stage of blastocyst development, and Northern blotting confirmed that antiluteolysin mRNA production occurred between days 13 and 22 after oestrus. This is consistent with the stage at which embryonic extracts are antiluteolytic on administration in vivo. These and other data confirm that the ovine trophoblast antiluteolysin is an interferon, and suggest that at least five isoforms of this protein may exist.

scholarly journals Advances in Photoacoustic Noninvasive Glucose Testing

1999 ◽  
Vol 45 (9) ◽  
pp. 1587-1595 ◽  
Author(s):  
Hugh A MacKenzie ◽  
Helen S Ashton ◽  
Stephen Spiers ◽  
Yaochun Shen ◽  
Scott S Freeborn ◽  
...  
Keyword(s):  
Glucose Measurement ◽  
Oral Glucose ◽  
Physiological Factors ◽  
Glucose Testing ◽  
In Vivo Experiments ◽  
In Vitro Measurements ◽  
Clinical Measurements ◽  
Blood Analytes

Abstract We report here on in vitro and in vivo experiments that are intended to explore the feasibility of photoacoustic spectroscopy as a tool for the noninvasive measurement of blood glucose. The in vivo results from oral glucose tests on eight subjects showed good correlation with clinical measurements but indicated that physiological factors and person-to-person variability are important. In vitro measurements showed that the sensitivity of the glucose measurement is unaffected by the presence of common blood analytes but that there can be substantial shifts in baseline values. The results indicate the need for spectroscopic data to develop algorithms for the detection of glucose in the presence of other analytes.

scholarly journals An in vivo and in vitro assessment of TOR signaling cascade in rainbow trout (Oncorhynchus mykiss)

2008 ◽  
Vol 295 (1) ◽  
pp. R329-R335 ◽  
Author(s):  
Iban Seiliez ◽  
Jean-Charles Gabillard ◽  
Sandrine Skiba-Cassy ◽  
Daniel Garcia-Serrana ◽  
Joaquim Gutiérrez ◽  
...  
Keyword(s):  
Rainbow Trout ◽  
Amino Acid ◽  
Mammalian Target Of Rapamycin ◽  
Mrna Translation ◽  
Target Of Rapamycin ◽  
Nutritional Regulation ◽  
Tor Signaling ◽  
Meal Feeding

In mammals, feeding promotes protein accretion in skeletal muscle through a stimulation of the insulin- and amino acid- sensitive mammalian target of rapamycin (mTOR) signaling pathway, leading to the induction of mRNA translation. The purpose of the present study was to characterize both in vivo and in vitro the activation of several major kinases involved in the mTOR pathway in the muscle of the carnivorous rainbow trout. Our results showed that meal feeding enhanced the phosphorylation of the target of rapamycin (TOR), PKB, p70 S6 kinase, and eIF4E-binding protein-1, suggesting that the mechanisms involved in the regulation of mRNA translation are well conserved between lower and higher vertebrates. Our in vitro studies on primary culture of trout muscle cells indicate that insulin and amino acids regulate TOR signaling and thus may be involved in meal feeding effect in this species as in mammals. In conclusion, we report here for the first time in a fish species, the existence and the nutritional regulation of several major kinases involved in the TOR pathway, opening a new area of research on the molecular bases of amino acid utilization in teleosts.

scholarly journals Hypoglycemic Efficacy of Docking Selected Natural Compounds against α-Glucosidase and α-Amylase

Molecules ◽  
2018 ◽  
Vol 23 (9) ◽  
pp. 2260 ◽  
Author(s):  
Jirawat Riyaphan ◽  
Chien-Hung Jhong ◽  
Shian-Ren Lin ◽  
Chia-Hsiang Chang ◽  
May-Jwan Tsai ◽  
...  
Keyword(s):  
Molecular Docking ◽  
Herbal Medicines ◽  
Natural Compounds ◽  
Cell System ◽  
Oral Glucose ◽  
Glucose Levels ◽  
In Vivo Experiments ◽  
Sugar Levels

The inhibition of α-glucosidase and α-amylase is a clinical strategy for the treatment of type II diabetes, and herbal medicines have been reported to credibly alleviate hyperglycemia. Our previous study has reported some constituents from plant or herbal sources targeted to α-glucosidase and α-amylase via molecular docking and enzymatic measurement, but the hypoglycemic potencies in cell system and mice have not been validated yet. This study was aimed to elucidate the hypoglycemic efficacy of docking selected compounds in cell assay and oral glucose and starch tolerance tests of mice. All test compounds showed the inhibition of α-glucosidase activity in Caco-2 cells. The decrease of blood sugar levels of test compounds in 30 min and 60 min of mice after OGTT and OSTT, respectively and the decreased glucose levels of test compounds were significantly varied in acarbose. Taken altogether, in vitro and in vivo experiments suggest that selected natural compounds (curcumin, antroquinonol, HCD, docosanol, tetracosanol, rutin, and actinodaphnine) via molecular docking were confirmed as potential candidates of α-glucosidase and α-amylase inhibitors for treating diabetes.

scholarly journals Role of Bioactive Peptide Sequences in the Potential Impact of Dairy Protein Intake on Metabolic Health

2020 ◽  
Vol 21 (22) ◽  
pp. 8881
Author(s):  
Giovanni Tulipano
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Energy Balance ◽  
Bioactive Compounds ◽  
Glucose Homeostasis ◽  
Protein Intake ◽  
Body Weight Gain ◽  
Dairy Protein

For years, there has been an increasing move towards elucidating the complexities of how food can interplay with the signalling networks underlying energy homeostasis and glycaemic control. Dairy foods can be regarded as the greatest source of proteins and peptides with various health benefits and are a well-recognized source of bioactive compounds. A number of dairy protein-derived peptide sequences with the ability to modulate functions related to the control of food intake, body weight gain and glucose homeostasis have been isolated and characterized. Their being active in vivo may be questionable mainly due to expected low bioavailability after ingestion, and hence their real contribution to the metabolic impact of dairy protein intake needs to be discussed. Some reports suggest that the differential effects of dairy proteins—in particular whey proteins—on mechanisms underlying energy balance and glucose-homeostasis may be attributed to their unique amino acid composition and hence the release of free amino acid mixtures enriched in essential amino acids (i.e., branched-chain-amino acids) upon digestion. Actually, the research reports reviewed in this article suggest that, among a number of dairy protein-derived peptides isolated and characterized as bioactive compounds in vitro, some peptides can be active in vivo post-oral administration through a local action in the gut, or, alternatively, a systemic action on specific molecular targets after entering the systemic circulation. Moreover, these studies highlight the importance of the enteroendocrine system in the cross talk between food proteins and the neuroendocrine network regulating energy balance.

scholarly journals Molecular cloning and expression analysis of rainbow trout (Oncorhynchus mykiss) CCAAT/enhancer binding protein genes and their responses to induction by GH in vitro and in vivo

2007 ◽  
Vol 194 (2) ◽  
pp. 393-406 ◽  
Author(s):  
Jay H Lo ◽  
Pinwen Peter Chiou ◽  
C M Lin ◽  
Thomas T Chen
Keyword(s):  
Rainbow Trout ◽  
Oncorhynchus Mykiss ◽  
Cloning And Expression ◽  
Mrna Levels ◽  
Specific Expression ◽  
Rainbow Trout Oncorhynchus Mykiss ◽  
Enhancer Binding Protein ◽  
Previous Hypothesis

CCAAT/enhancer-binding proteins (C/EBPs) are transcription factors consisting of six isoforms and play diverse physiological roles in vertebrates. In rainbow trout (Oncorhynchus mykiss), in addition to the reported C/EBPβ1, we have isolated cDNA of four other isoforms, C/EBPα, C/EBPβ2, C/EBPδ1, C/EBPδ2, from the liver. Comparison of the deduced amino acid sequence of rainbow trout C/EBPs with those of other vertebrates revealed that C/EBP isoforms are highly conserved. The profiles of tissue-specific expression of individual C/EBP isoform mRNA, determined by quantitative real-time (RT)-PCR showed distinct patterns. Furthermore, injection of bovine GH into yearling rainbow trout resulted in a significant increase of mRNA levels of C/EBPβ1, C/EBPβ2, and C/EBPδ2 but not C/EBPα and C/EBPδ1 in the liver. GH-dependent increase of mRNA levels of C/EBPβ1, C/EBPβ2, C/EBPδ2, and IGF-II were also confirmed by treating rainbow trout hepatoma cells expressing a goldfish GH receptor with bGH. Together with our previous findings, the results presented in this paper strengthen our previous hypothesis that GH may regulate the expression of the IGF-II gene via mediating the expression of C/EBPβ1, C/EBPβ2, and C/EBPδ2 mRNA.

scholarly journals Expression of CD14 by Hepatocytes: Upregulation by Cytokines during Endotoxemia

1998 ◽  
Vol 66 (11) ◽  
pp. 5089-5098 ◽  
Author(s):  
Shubing Liu ◽  
Lajwanti S. Khemlani ◽  
Richard A. Shapiro ◽  
Mark L. Johnson ◽  
Kaihong Liu ◽  
...  
Keyword(s):  
Amino Acid ◽  
Rat Hepatocytes ◽  
Amino Acid Sequences ◽  
Mrna Levels ◽  
Soluble Cd14 ◽  
Protein Levels ◽  
Cd14 Mrna ◽  
Lps Treatment

ABSTRACT Studies were undertaken to examine hepatocyte CD14 expression during endotoxemia. Our results show that lipopolysaccharide (LPS) treatment in vivo caused a marked upregulation in CD14 mRNA and protein levels in rat hepatocytes. Detectable increases in mRNA were seen as early as 1.5 h after LPS treatment; these increases peaked at 20-fold by 3 h and returned to baseline levels by 24 h. In situ hybridization localized the CD14 mRNA expression to hepatocytes both in vitro and in vivo. Increases in hepatic CD14 protein levels were detectable by 3 h and peaked at 12 h. Hepatocytes from LPS-treated animals expressed greater amounts of cell-associated CD14 protein, and more of the soluble CD14 was released by hepatocytes from LPS-treated rats in vitro. The increases in hepatocyte CD14 expression during endotoxemia occurred in parallel to increases of CD14 levels in plasma. To provide molecular identification of the hepatocyte CD14, we cloned the rat liver CD14 cDNA. The longest clone consists of a 1,591-bp insert containing a 1,116-bp open reading frame. The deduced amino acid sequence is 372 amino acids long, has 81.8 and 62.8% homology to the amino acid sequences of mouse and human CD14, respectively, and is identical to the rat macrophage CD14. The expressed CD14 protein from this clone was functional, as indicated by NF-κB activation in response to LPS and fluorescein isothiocyanate-LPS binding in CHO cells stably transfected with rat CD14. A nuclear run-on assay showed that CD14 transcription rates were significantly increased in hepatocytes from LPS-treated animals, indicating that the upregulation in CD14 mRNA levels observed in rat hepatocytes after LPS treatment is dependent, in part, on increased transcription. In vitro and in vivo experiments indicated that interleukin-1β and/or tumor necrosis factor α participate in the upregulation of CD14 mRNA levels in hepatocytes. Our data indicate that hepatocytes express CD14 and that hepatocyte CD14 mRNA and protein levels increase rapidly during endotoxemia. Our observations also support the idea that soluble CD14 is an acute-phase protein and that hepatocytes could be a source for soluble CD14 production.

Salmon calcitonin inhibits whole body Ca2+ uptake in young rainbow trout

1997 ◽  
Vol 155 (3) ◽  
pp. 459-465 ◽  
Author(s):  
GF Wagner ◽  
EM Jaworski ◽  
DP Radman
Keyword(s):  
Rainbow Trout ◽  
Transport Process ◽  
Plasma Calcium ◽  
Whole Body ◽  
Mrna Levels ◽  
Inhibitory Effects ◽  
Negative Regulators

Gill Ca2+ transport (GCAT) in fish is regulated by a number of different hormones. Stanniocalcin (STC) from the corpuscles of Stannius (CS) is an inhibitor of GCAT, whereas pituitary-derived prolactin and cortisol stimulate GCAT. Other than this, however, little is known about the effects of other hormones on this important transport process. The role of calcitonin (CT) in calcium homeostasis in fish is still controversial. Whereas many studies have shown significant effects of CT on plasma calcium levels, an equal number of studies have failed to find any correlations between plasma calcium and CT levels in fish. Previous in vitro studies have shown that salmon CT has potent inhibitory effects on GCAT in isolated, perfused fish gill preparations, a finding that has never been corroborated in vivo. Therefore, in this report we examined the effects of salmon CT on whole body 45Ca uptake (as a measure of GCAT) in young rainbow trout. In support of the in vitro findings, we found that CT had significant inhibitory effects on GCAT. In parallel studies, we found that CT had no effects on STC secretion and only modest, stimulatory effects on STC mRNA levels in cultured trout CS cells. These finding suggest that both CT and STC function as negative regulators of GCAT in fish.

scholarly journals Preparation and Evaluation of the Effect of Acetyl Hexapeptide-8 Ampoule for Scalp Treatment

2021 ◽  
Vol 19 (3) ◽  
pp. 435-444
Author(s):  
Hae-Won Jo ◽  
Kyung-Hee Lee ◽  
Jeong-Hee Kim
Keyword(s):  
In Vitro Cytotoxicity ◽  
Integrin Subunit ◽  
Mrna Levels ◽  
Dependent Manner ◽  
Hacat Cells ◽  
Skin Reactions ◽  
In Vivo Experiments ◽  
Irritation Test

Purpose: The topical application of scalp-care cosmetics, infused with functional ingredients, can offer an optimal cosmetic approach to prevent problems associated with aging. In terms of the development of anti-aging cosmetics, we studied the use of acetyl hexapeptide-8 (AH-8) for improving elasticity of the scalp.Methods: Ampoules containing 3% and 5% concentrations of AH-8 as an active ingredient were prepared and their safety and efficacy were evaluated. HaCaT cells were used to evaluate the safety of AH-8 ampoules by measurement of in vitro cytotoxicity. In in vivo experiments, we tested the AH-8 ampoules by cumulative irritation test (CIT) on healthy adults, 20–50 years of age. Relative expressions of superoxide dismutase 2 (SOD2), forkhead box O1 (FOXO1), actinin alpha 1 (ACTN1), collagen type XVII alpha 1 chain (COL17A1), and integrin subunit beta 4 (ITGB4) were assessed using quantitative real-time PCR (Q-PCR).Results: AH-8 ampoules showed significant cytotoxicity to HaCaT cells in a dose-dependent manner. CIT assessment in 30 adults revealed no skin reactions to both 3% and 5% AH-8 ampoules. After treatment of HaCaT cells with the AH-8 ampoules, mRNA levels of SOD2 and FOXO1, which are directly implicated as antioxidant factors, were increased. Of the factors that improve elasticity, ACTN1 mRNA levels had the greatest increase when treated with the 5% AH-8 ampoules (1.75 µg/mL). Also, the AH-8 ampoules increased mRNA levels of COL17A1, and ITGB4 in HaCaT cells.Conclusions: In this study, we proved that 3% and 5% AH-8 ampoules are safe for use as a scalp-care cosmetic. AH-8 ampoule had efficacy in anti-aging and improving elasticity of the scalp. This comprehensive test showed that AH-8 can be developed as a cosmetic for anti-aging and improvement of scalp elasticity.

scholarly journals Kinetics of Branchial Calcium Uptake in the Rainbow Trout: Effects of Acclimation to Various External Calcium Levels

1985 ◽  
Vol 116 (1) ◽  
pp. 411-433 ◽  
Author(s):  
S. F. PERRY ◽  
C. M. WOOD
Keyword(s):  
Rainbow Trout ◽  
Calcium Uptake ◽  
Chloride Cells ◽  
Arterial Circulation ◽  
In Vivo Experiments ◽  
Kinetics Of ◽  
Fold Stimulation ◽  
External Calcium

Calcium uptake (JCain) in freshwater rainbow trout (Salmo gairdnen) under control conditions (external [Ca2+] ≃ 1.8 mequivl−1, [NaCl] ≃ 0.8 mequiv 1−1) occurred at approximately equal rates (12–15 μequiv kg−1 h−1) through the gills and the general body surface in vivo. The gut was not involved. Under the same conditions, in vitro branchial JCain in an isolated, saline-perfused head preparation was equal to that in vivo. The cells involved in JinCa are mainly located on lamellae rather than on filaments since 95 % of JinCa occurred across the arterio-arterial circulation of the gill. JinCa, in vitro, displayed Michaelis-Menten kinetics. Acclimation to low external [Ca2+] (50 μequiv 1−1; unchanged [NaCl]) for 1 day caused a five-fold stimulation of JinCa characterized by decreased Km and increased J max. Longer periods of low [Ca2+] acclimation resulted in changes of Jmax only. Jmax gradually returned towards control levels as acclimation time increased, but was still elevated after 30 days. Acclimation to low ambient [Ca2+] caused proliferation and increased exposure of lamellar chloride cells which were correlated with increased Jmax. Fish exposed to high external [Ca2+] (10 mequivl−1; unchanged [NaCl]) displayed reduced JinCa Similar changes in JinCa were observed during in vivo experiments. Plasma Ca2+ concentration remained constant regardless of external [Ca2+], while plasma Na+ and Cl− levels were transiently reduced at 1 day low [Ca2+] exposure but had recovered by 7 days. A possible role for cortisol in Ca2+ regulation is discussed based on observations of cortisol-stimulated lamellar chloride cell proliferation and JinCa, and elevated plasma [cortisol] in low-[Ca2+] acclimated fish.

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