Plasma NEFA Levels Research Articles

THU047 Growth Hormone (GH) Signaling In Hepatocytes Controls Hepatic Insulin Sensitivity And Nutrient Disposition

Abstract Disclosure: M. del Rio-Moreno: None. M. Vazquez-Borrego: None. J. Cordoba-Chacon: None. O.P. McGuinness: None. R.D. Kineman: None. It is commonly accepted that GH reduces the actions of insulin. However, we reported plasma GH levels within a physiological range are negatively associated with insulin-mediated glucose uptake, but positively associated with insulin-mediated suppression of hepatic glucose production (HGP) [Cordoba-Chacon J. et al. 2014. AJP Endocrinol Metab]. These findings suggest that GH may promote insulin’s actions on the liver. To determine the direct contribution of GH signaling on hepatic insulin sensitivity, hyperinsulinemic-euglycemic clamps were performed with stable isotope tracers in chow-fed adult-onset, hepatocyte-specific GHR knockdown (aHepGHRkd) mice. aHepGHRkd mice show reduced IGF1 and increased GH levels [Cordoba-Chacon J. et al 2015, Diabetes] which indirectly impacts systemic insulin sensitivity and substrate flux to the liver. To normalize plasma IGF1 and GH levels, aHepGHRkd mice were co-treated with adeno-associated virus (AAV) that express IGF1 or a constitutively active form of STAT5b (STAT5bCA). These AAVs have a thyroxin binding globulin promoter, leading to hepatocyte-specific expression. Under both basal and clamped conditions, aHepGHRkd mice exhibited hyperinsulinemia, that was normalized by AAV-mediated IGF1 and STAT5bCA expression. Interestingly, glucose disappearance (Rd), tissue-specific glucose uptake, or HGP (gluconeogenesis and glycogenolysis) did not differ across all groups. However, higher insulin tone in aHepGHRkd mice was required to achieve the same level of Rd and suppression of HGP in the steady-state, which was indicative of systemic and hepatic insulin resistance. These observations are consistent with our previous findings that GH reduces tissue-specific glucose uptake but promotes insulin-mediated control of HGP. In contrast, aHepGHRkd mice exhibited an increased rate of hepatic de novo lipogenesis, and an increase in plasma levels of newly formed triglyceride and triglyceride-bound palmitate, that was normalized by IGF1 and STAT5bCA expression. Taken together, these results indicate loss of hepatocyte GH signaling leads to pathway selective hepatic insulin resistance. This pathway selective hepatic insulin resistance has also been reported in mouse models due to altered substrate delivery to the liver as consequence of excess dietary intake and/or increased adipose tissue lipolysis. However, chow-fed aHepGHRkd mice show hyperinsulinemia that was sufficient to normalize systemic glucose uptake and suppress WAT lipolysis, as noted by normal plasma NEFA levels under both basal and clamped conditions. Therefore, changes in substrate delivery to the liver cannot readily explain the changes observed, suggesting hepatocyte GHR-signaling plays a direct role in partitioning of hepatic nutrients in response to insulin. Presentation: Thursday, June 15, 2023

Direct and systemic actions of growth hormone receptor (GHR)-signaling on hepatic glycolysis, de novo lipogenesis and insulin sensitivity, associated with steatosis

BackgroundEvidence is accumulating that growth hormone (GH) protects against the development of steatosis and progression of non-alcoholic fatty liver disease (NAFLD). GH may control steatosis indirectly by altering systemic insulin sensitivity and substrate delivery to the liver and/or by the direct actions of GH on hepatocyte function. ApproachTo better define the hepatocyte-specific role of GH receptor (GHR) signaling on regulating steatosis, we used a mouse model with adult-onset, hepatocyte-specific GHR knockdown (aHepGHRkd). To prevent the reduction in circulating insulin-like growth factor 1 (IGF1) and the subsequent increase in GH observed after aHepGHRkd, subsets of aHepGHRkd mice were treated with adeno-associated viral vectors (AAV) driving hepatocyte-specific expression of IGF1 or a constitutively active form of STAT5b (STAT5bCA). The impact of hepatocyte-specific modulation of GHR, IGF1 and STAT5b on carbohydrate and lipid metabolism was studied across multiple nutritional states and in the context of hyperinsulinemic:euglycemic clamps. ResultsChow-fed male aHepGHRkd mice developed steatosis associated with an increase in hepatic glucokinase (GCK) and ketohexokinase (KHK) expression and de novo lipogenesis (DNL) rate, in the post-absorptive state and in response to refeeding after an overnight fast. The aHepGHRkd-associated increase in hepatic KHK, but not GCK and steatosis, was dependent on hepatocyte expression of carbohydrate response element binding protein (ChREBP), in re-fed mice. Interestingly, under clamp conditions, aHepGHRkd also increased the rate of DNL and expression of GCK and KHK, but impaired insulin-mediated suppression of hepatic glucose production, without altering plasma NEFA levels. These effects were normalized with AAV-mediated hepatocyte expression of IGF1 or STAT5bCA. Comparison of the impact of AAV-mediated hepatocyte IGF1 versus STAT5bCA in aHepGHRkd mice across multiple nutritional states, indicated the restorative actions of IGF1 are indirect, by improving systemic insulin sensitivity, independent of changes in the liver transcriptome. In contrast, the actions of STAT5b are due to the combined effects of raising IGF1 and direct alterations in the hepatocyte gene program that may involve suppression of BCL6 and FOXO1 activity. However, the direct and IGF1-dependent actions of STAT5b cannot fully account for enhanced GCK activity and lipogenic gene expression observed after aHepGHRkd, suggesting other GHR-mediated signals are involved. ConclusionThese studies demonstrate hepatocyte GHR-signaling controls hepatic glycolysis, DNL, steatosis and hepatic insulin sensitivity indirectly (via IGF1) and directly (via STAT5b). The relative contribution of these indirect and direct actions of GH on hepatocytes is modified by insulin and nutrient availability. These results improve our understanding of the physiologic actions of GH on regulating adult metabolism to protect against NAFLD progression.

Effect of Milk Thistle (Silybum marianum) Seed Cakes by Horses Subjected to Physical Exertion

Milk thistle (Silybum marianum) provides several possible benefits for horses, namely anti–inflammatory, antioxidant effects, hepatoprotective, and neuroprotective effects. Silybin exerts also pronounced effects on energy metabolism, that could be useful for sport horses. The aim of this study is to evaluate the effect of milk thistle seed cakes (in the form of a granulated mixture with barley) on blood biochemical parameters (total protein, albumin, bilirubin, urea, creatinine, ALT, AST, ALP, GGT, LDH, the total cholesterol, HDL-cholesterol, LDL-cholesterol, TAG, BHB, NEFA, creatine kinase, lactate, glucose, glutathione peroxidase, total antioxidant capacity, cortisol, calcium, and phosphorus) to monitor the differences between the experimental (milk thistle in feed) and control horses after exposure of the monitored horses to heavy physical exercise (combined driving) total number of horses was 12 Czech Warmblood breed horses. The digestibility of silymarin (and its individual flavonolignans) and basic nutrients are also monitored in this study. Statistically significant differences (P < .05) were found mainly in plasma cortisol and NEFA levels. The results of this study confirmed the results of our previous studies. These results suggest that the feeding of milk thistle seed cakes has a possible positive effect on horse health and energy metabolism.

Physio-biochemical responses and growth performance of buffalo heifers to betaine supplementation during hot humid season under field conditions

In order to find out the effect of betaine supplementation on physiological (rectal temperature, skin temperature, respiration rate and pulse rate) responses, morphological (body length, heart girth and height at withers) parameters, stress markers (cortisol and NEFA levels), growth hormone, dry matter intake (DMI) and body weight of buffalo heifers during hot humid season under field conditions, 14 buffalo heifers were selected and equally divided into 2 groups, i.e. control and treatment (supplemented betaine @ 25 g/animal/day over the farmers practice). Blood samples were collected at fortnightly interval from both the groups and analyzed for stress markers. THI was calculated for measuring the stress levels on buffalo heifers, which remained 􀀡76 indicating severe stress. Physiological responses were significantly lower in treatment group than control. Morphological parameters, body weight and DMI were higher in treatment than control. Plasma cortisol and NEFA levels were significantly lower, whereas plasma growth hormone was significantly higher in treatment group compared to control. ADG was significantly higher in treatment group compared to control. Positive correlation was observed between THI and stress markers, physiological responses and negatively correlated with ADG, DMI and growth hormone. It can be concluded that betaine acted as a potent growth promoter by lowering the levels of stress markers and enhancing the ADG and DMI of buffalo heifers.

Betatrophin knockdown induces beiging and mitochondria biogenesis of white adipocytes.

Remodeling of energy-storing white fat into energy-consuming beige fat has led to a promising new approach to alleviate adiposity. Several studies have shown adipokines can induce white adipose tissue (WAT) beiging through autocrine or paracrine actions. Betatrophin, a novel adipokine, has been linked to energy expenditure and lipolysis but not clearly clarified. Here, we using high-fat diet-induced obesity to determine how betatrophin modulate beiging and adiposity. We found that betatrophin-knockdown mice displayed less white fat mass and decreased plasma TG and NEFA levels. Consistently, inhibition of betatrophin leads to the phenotype change of adipocytes characterized by increased mitochondria contents, beige adipocytes and mitochondria biogenesis-specific markers both in vivo and in vitro. Of note, blocking AMP-activated protein kinase (AMPK) signaling pathway is able to abolish enhanced beige-like characteristics in betatrophin-knockdown adipocytes. Collectively, downregulation of betatrophin induces beiging in white adipocytes through activation of AMPK signaling pathway. These processes suggest betatrophin as a latent therapeutic target for obesity.

Lipid profile and liver lipids of OLETF rats during ARB treatment and after its removal

The metabolic syndrome (MetS) affects 20% of the US population. MetS comprises several disorders that raise the risk of atherosclerosis, insulin resistance, and diabetes. Angiotensin receptor blockers (ARBs) are used to ameliorate hypertension associated with metabolic disorders. Nonetheless, the potential benefits of ARBs on the metabolic state are not fully appreciated. ARB treatment reduces overproduction and accumulation of hepatic triacylglycerols (TAG), but whether ARB treatment has favorable effects in fatty livers associated with insulin resistance is still unknown. Furthermore, the compliance on the usage of ARBs should also be addressed, as MetS patients may be under variating treatments, exposing them to secondary effects due to the ARB treatment removal. To evaluate the benefits of ARB treatment and implications of its removal on the lipid profile, four groups (n=4–6) of 25‐week‐old rats were used: (1) lean, strain‐control Long‐Evans Tokoshima Otsuka (LETO), (2) obese, insulin resistant Otsuka Long‐Evans Tokoshima Fatty (OLETF), 3) ARB‐treated OLETF, (10 mg olmesartan/kg/d × 8 wks), and 4) OLETF ± ARB (10 mg olmesartan/kg/d × 4 wks then removed until dissection). An oral glucose challenge (GC) was performed prior to dissection and tissues collected from a subset of animals in each group at defined time points (T0, 3 an 6hr). We measured different components of the lipid profile, during the ARB treatment and after its removal. Plasma NEFA, TAG and cholesterol levels remain unchanged with ARB treatment, as well as with ARB removal. ARB treatment did not change the liver levels of cholesterol, but prevented the increase shown by OLETFs during the GC. ARB removal shown increased cholesterol after 6 hr of the GC. ARB treatment decreased liver TAG and throughout the GC. ARB removal increased TAG liver levels during the GC. Suggesting that lipid profiles may not change during static sampling during or after ARB treatment. ARB treatment reduces liver TAG concentration, and even with ARB removal suggesting that plasma levels do not accurately reflect tissue levels. Following the GC, the ARB removal group demonstrated an increase in levels, suggesting that treatment non‐compliance results in rapid return to basal levels and increased potential for hepatic dysfunction. Further investigation on lipid transport and metabolic regulation during ARB treatment and removal may yield insight for a wider perspective for treatment of traits linked to MetS.Support or Funding InformationThis work was supported by NIH MHIRT.

Effects of &amp;lt;i&amp;gt;γ&amp;lt;/i&amp;gt;-Polyglutamic Acid on Blood Glucose and Caecal Short Chain Fatty Acids in Adult Male Mice

γ-Polyglutamic acid (γ-PGA) is a major component of Natto. We hypothesized that γ-PGA could reduce postprandial glucose rise and plasma glucose levels. Mice were fed a 0.1% γ-PGA—containing diet or control diet for 91 days. Maltose and starch tolerance tests were performed, and plasma lipids, glucose levels, and caecal short chain fatty acids (SCFAs) were measured. Mice were co-administered γ-PGA and starch to suppress the initial rise in blood glucose levels. Blood glucose levels at 15 min were significantly lower in the PGA group than in the Con group (P 0.05). The plasma glucose level and NEFA level were also significantly lower in the PGA group (P 0.05), and caecal acetic acid/total caecal SCFAs ratio was significantly increased in the PGA group (P 0.05). Significant negative correlations existed between the caecal acetic acid/propionic acid ratio and the weight of visceral fat/BW (r = -0.57, P = 0.0318). Our results suggest that γ-PGA may effectively prevent metabolic syndrome by lowering blood glucose levels.

Association between breakfast skipping and postprandial hyperglycaemia after lunch in healthy young individuals.

Breakfast skipping has become an increasing trend in the modern lifestyle and may play a role in obesity and type 2 diabetes. In our previous studies in healthy young individuals, a single incident of breakfast skipping increased the overall 24-h blood glucose and elevated the postprandial glycaemic response after lunch; however, it was difficult to determine whether this response was due to breakfast omission or the extra energy (i.e. lunch plus breakfast contents). The present study aimed to assess the postprandial glycaemic response and to measure their hormone levels when healthy young individuals had identical lunch and dinner, and the 24-h average blood glucose as a secondary outcome. Nine healthy young men (19-24 years) participated in two-meal trials: with breakfast (three-meal condition) or without breakfast (breakfast skipping condition). During the meals, each individual's blood glucose was continuously monitored. Skipping breakfast resulted in a significantly higher (P < 0·001) glycaemic response after lunch as compared with the glycaemic response after an identical lunch when breakfast was consumed. Despite the difference in the total energy intake, the 24-h average blood glucose was similar between the two-meal conditions (P = 0·179). Plasma NEFA level was significantly higher (P < 0·05) after lunch when breakfast was omitted, and NEFA level positively correlated with the postprandial glycaemic response (r 0·631, P < 0·01). In conclusion, a single incident of breakfast skipping increases postprandial hyperglycaemia, and associated impaired insulin response, after lunch. The present study showed that skipping breakfast influences glucose regulation even in healthy young individuals.

270-OR: Adipocyte Integrin-Linked Kinase Is Necessary for the Development of Diet-Induced Adipose Insulin Resistance

The remodeling of the extracellular matrix (ECM) in tissues including adipose tissue, and the expression of collagen binding integrin α2β1 have been associated with the development of insulin resistance. Integrin-linked Kinase (ILK), an adaptor protein and a key component of the IPP (ILK-Parvin-PINCH) complex mediates integrins linking the ECM with intracellular signalling. This study determines the role of ILK in adipose function and insulin resistance in chow and high fat (HF)-fed mice. HF feeding increased adipose ILK expression in mice (2.7 ±0.62 vs. 1±0.23; p=0.01). Adipocyte-specific deletion of ILK resulted in a decrease in fat mass (21.6±1.6% vs. 27.3±1.4%; p=0.009) and epididymal tissue weight (eWAT) (1.04±0.07g vs. 1.62±0.11g; p&amp;lt;0.001) in HF-fed mice, but not in chow-fed mice. During the hyperinsulinemic-euglycemic clamp, HF-fed ILK deficient mice showed increased glucose uptake (66.22±p=0.028) in the brown adipose tissue (BAT) compared with the wild type littermate controls. Increased glucose uptake in BAT is associated with increased phosphorylation of AKT (1.96±0.16 vs. 1±0.28 fold change; p=0.01), and decreased phosphorylation of p38 and JNK (0.23 ± 0.17 vs. 1±0.48; p=0.024 and 0.41 ±0.12 vs. 1±0.17; p=0.025 respectively). The inhibition of lipolysis by insulin was also improved in HF-fed ILK deficient mice determined by plasma NEFA level during the clamp. This could be attributed to decreased cell size (0.85±0.042 vs. 1±0.06; p=0.0001), decreased collagen deposition (22.8±0.98 vs. 30.28± 2.05; p=0.01) and a trend increase in vascularization (3.47±1.26 vs. 1±0.23; p=0.07) in the eWAT. These data suggest that adipocyte ILK plays an important role in regulating adipocyte morphology, signaling and glucose and lipid homeostasis, therefore representing a potential target for obesity, insulin resistance and diabetes. Disclosure A. Bugler-Lamb: None. C. Hennayake: None. A. Hasib: None. M.L. Ashford: None. L. Kang: None. Funding Diabetes UK; Diabetes Research &amp; Wellness Foundation

SAT-152 Loss of Hepatocyte PPARγ Expression Ameliorates Steatosis in Mice Fed a High-Fat, Cholesterol, and Fructose Diet, but Not in Mice Fed a Methionine- and Choline-Deficient Diet

Hepatic PPARγ expression is positively associated with the progression of non-alcoholic fatty liver disease and non-alcoholic steatohepatitis (NASH) in mice and humans. Although PPARγ agonists, thiazolidinediones (TZD), could be used to treat patients with NASH, these drugs reduced steatosis only in some patients with NASH, while it exacerbated steatosis in obese mice. Several mouse models with congenital knockout or overexpression of hepatic PPARγ have been used to study the actions and relevance of hepatocyte PPARγ in the development of steatosis. However, the mechanisms that hepatocyte PPARγ regulates to promote steatosis are not fully understood. Our group has previously reported that adult-onset hepatocyte-specific PPARγ knockout (aHepPPARγKO) mice fed a high fat diet (60% Kcal from fat) developed adiposity similar to PPARγ-intact controls, but aHepPPARγKO mice showed a dramatic reduction in steatosis, associated with reduced hepatic Cd36-mediated fatty acid uptake. Here, we fed aHepPPARγKO mice two different diets that produce steatosis and NASH to determine if loss of hepatocyte PPARγ expression reduced hepatic lipid levels associated with a reduction in Cd36 expression. Specifically, aHepPPARγKO and control mice were generated by injecting 10 wk-old male PPARγ-floxed littermate mice with a single dose of adeno-associated virus serotype 8 (AAV8) expressing hepatocyte-specific Cre recombinase or a AAV8-null vector, respectively. Two weeks later, aHepPPARγKO and control mice were fed either a methionine- and choline-deficient diet (MCD) for 3 weeks or a high-fat, cholesterol and fructose diet (HFCFD) diet for 8 weeks. The expression of hepatic PPARγ and Cd36 was significantly increased in MCD- and HFCF-fed control mice as compared to their respective control diet-fed controls. Of note, aHepPPARγKO reduced the expression of hepatic PPARγ (by >85%) and Cd36 (by >35-65%). Overall, MCD-fed mice showed reduced body weight, fat mass, and plasma cholesterol levels, while HFCFD-fed mice showed increased body weight and gonadal fat mass, and reduced plasma NEFA levels as compared to their respective control diet-fed littermates. Independent of diet, aHepPPARγKO did not alter body weight, adiposity, or the levels of plasma lipids. However, aHepPPARγKO reduced steatosis in HFCFD-fed mice, but not in MCD-fed mice. Interestingly, the levels of hepatic oleic [18:1(n-9)] and linoleic [18:2(n-6)] acids were, in fact, increased in MCD-fed aHepPPARγKO mice, while the levels of hepatic palmitoleic [16:1(n-7)] and oleic [18:1(n-9)] acids were reduced in HFCFD-fed aHepPPARγKO mice. Taken together, these data suggest that hepatocyte PPARγ serves as a steatogenic factor only in HFCFD-fed mice and not in MCD-fed mice, and this may be due to diet-dependent effects: nature of the development of steatosis and/or changes in adipose tissue.

Increased NEFA levels reduce blood Mg2+ in hypertriacylglycerolaemic states via direct binding of NEFA to Mg2+

Aims/hypothesisThe blood triacylglycerol level is one of the main determinants of blood Mg2+ concentration in individuals with type 2 diabetes. Hypomagnesaemia (blood Mg2+ concentration <0.7 mmol/l) has serious consequences as it increases the risk of developing type 2 diabetes and accelerates progression of the disease. This study aimed to determine the mechanism by which triacylglycerol levels affect blood Mg2+ concentrations.MethodsUsing samples from 285 overweight individuals (BMI >27 kg/m2) who participated in the 300-Obesity study (an observational cross-sectional cohort study, as part of the Human Functional Genetics Projects), we investigated the association between serum Mg2+ with laboratory variables, including an extensive lipid profile. In a separate set of studies, hyperlipidaemia was induced in mice and in healthy humans via an oral lipid load, and blood Mg2+, triacylglycerol and NEFA concentrations were measured using colourimetric assays. In vitro, NEFAs harvested from albumin were added in increasing concentrations to several Mg2+-containing solutions to study the direct interaction between Mg2+ and NEFAs.ResultsIn the cohort of overweight individuals, serum Mg2+ levels were inversely correlated with triacylglycerols incorporated in large VLDL particles (r = −0.159, p ≤ 0.01). After lipid loading, we observed a postprandial increase in plasma triacylglycerol and NEFA levels and a reciprocal reduction in blood Mg2+ concentration both in mice (Δ plasma Mg2+ −0.31 mmol/l at 4 h post oral gavage) and in healthy humans (Δ plasma Mg2+ −0.07 mmol/l at 6 h post lipid intake). Further, in vitro experiments revealed that the decrease in plasma Mg2+ may be explained by direct binding of Mg2+ to NEFAs. Moreover, Mg2+ was found to bind to albumin in a NEFA-dependent manner, evidenced by the fact that Mg2+ did not bind to fatty-acid-free albumin. The NEFA-dependent reduction in the free Mg2+ concentration was not affected by the presence of physiological concentrations of other cations.Conclusions/interpretationThis study shows that elevated NEFA and triacylglycerol levels directly reduce blood Mg2+ levels, in part explaining the high prevalence of hypomagnesaemia in metabolic disorders. We show that blood NEFA level affects the free Mg2+ concentration, and therefore, our data challenge how the fractional excretion of Mg2+ is calculated and interpreted in the clinic.

Glucocorticoid‐Receptor Mediated Signaling Regulates Lipolysis in Northern Elephant Seal Pups

Northern elephant seals (NES) experience prolonged 2–3 month fasting periods, relying primarily on the oxidation of fatty acids to meet their energetic needs (RQ=0.71). Although fasting periods are characterized by an increase in circulating cortisol (F) and non‐esterified fatty acids (NEFA's), the functional relevance such increase in cortisol in NES is not defined. We hypothesized that F lipolysis is regulated through glucocorticoid receptor signaling (GR) in NES. The contributions of F and the GR were assessed by exogenous infusions of ACTH and/or concurrent blockade of the GR in the following groups: (1) untreated control, (2) ACTH (80 units intramuscular injection (IM)) and (3) ACTH + GR blocker (RU486) (80 units IM + 400mg RU486 in time release pellets). Plasma, and adipose and muscle biopsies were collected at days 0 (T0; immediately prior to infusion) and 6 (T6). Mean plasma NEFA levels increased 38% (0.84 ± 0.13 vs 1.16 ± 0.06mM) from T0 to T6 with ACTH infusion suggesting glucocorticoids contribute to increased lipolysis. ACTH infusion increased mean adipose HSP90 expression by 92%±18.2 while decreasing mean muscle HSP90 expression by 39%±14.5 from T0 to T6 suggesting that HSP90 may participate in GR‐mediated lipolysis in adipose while contributing to conserving lipid sources in muscle. Mean muscle CD36 expression decreased 46%±12.2 from T0 to T6 with ACTH infusion suggesting that there is a reduced intake of NEFA's by skeletal muscle, contributing to increased circulating NEFAs during lipolysis. These data suggest that the fasting‐associated increase in GR signaling is imperative for sustaining elevated levels of lipolysis during the post weaning fast, and is dependent upon the functional role of cortisol and HSP90.This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

Dietary soya protein improves intra-myocardial lipid deposition and altered glucose metabolism in a hypertensive, dyslipidaemic, insulin-resistant rat model.

This study investigates the effects of replacing dietary casein by soya protein on the underlying mechanisms involved in the impaired metabolic fate of glucose and lipid metabolisms in the heart of dyslipidaemic rats chronically fed (8 months) a sucrose-rich (62·5 %) diet (SRD). To test this hypothesis, Wistar rats were fed an SRD for 4 months. From months 4 to 8, half the animals continued with the SRD and the other half were fed an SRD in which casein was substituted by soya. The control group received a diet with maize starch as the carbohydrate source. Compared with the SRD-fed group, the following results were obtained. First, soya protein significantly (P<0·001) reduced the plasma NEFA levels and normalised dyslipidaemia and glucose homoeostasis, improving insulin resistance. The protein levels of fatty acid translocase at basal state and under insulin stimulation and the protein levels and activity of muscle-type carnitine palmitoyltransferase 1 were normalised. Second, a significant (P<0·001) reduction of TAG, long-chain acyl CoA and diacylglycerol levels was observed in the heart muscle. Third, soya protein significantly increased (P<0·01) GLUT4 protein level under insulin stimulation and normalised glucose phosphorylation and oxidation. A reduction of phosphorylated AMP protein kinase protein level was recorded without changes in uncoupling protein 2 and PPARα. Fourth, hydroxyproline concentration decreased in the left ventricle and hypertension was normalised. The new information provided shows the beneficial effects of soya protein upon the altered pathways of glucose and lipid metabolism in the heart muscle of this rat model.

Effect of Bypass Fat and Minerals Supplementation during Transitional Period on Plasma Levels of Thyroid Hormones, Metabolites and Postpartum Fertility in Crossbred Cows

Twenty healthy advanced pregnant crossbred (HF x K) cows of 2-4 parity were included in the study from 2 weeks prepartum to 8 weeks postpartum. They were equally divided in to control (routine farm feeding-RFF) and treatment (RFF plus area specific multi-minerals @ 50 g/h/d and bypass fat @ 100-200 g/h/d) groups to evaluate the effect of bypass fat and minerals supplementation on plasma metabolites and hormonal profile and postpartum fertility. The plasma levels of T3 increased (P less tha 0.01) on the day of calving and then abruptly dropped till day 14 postpartum as compared to levels at other periods, while T4 decreased (P less than 0.05) consistently throughout the study period particularly in control group. However, the influence of nutritional supplementation was found to be non-significant on both these hormones. The blood glucose levels were at peak concurrent to highest plasma cortisol on the day of calving. The cows under supplemented group had significantly (p less than 0.01) higher mean blood glucose (64.51±3.10 vs 59.13±3.06 mg/dl) and cortisol (16.19±2.51vs 11.23±1.34 ng/ml)than the control cows. The mean plasma levels of NEFA increased from day 14 prepartum to the highest (p less than 0.01) on the day of calving and thereafter reduced in postpartum days in both the groups with significantly higher mean value in supplemented than control group (0.58±0.09 vs 0.47±0.07 mmol/l). The prepartum plasma BHBA also increased as parturition approached, continued to increase further in the early postpartum period to reach a peak (1.21±0.09 and 0.87±0.04 mmol/l for control and treatment group) (p less than 0.01) on day 14, and thereafter decreased. In general, the plasma NEFA, BHBA, cortisol and glucose levels were found to be higher in the cows of nutrient supplemented group which had lesser time intervals for expressing first postpartum estrus and service period with better pregnancy rate. Thus the nutrient supplementation during transition period was beneficial in maintaining energy status of the cows and improved reproductive performance postpartum.

0309 HIGHER MORNING FASTING PLASMA NEFA LEVEL IS ASSOCIATED WITH WORSE QUALITY OF SLEEP AMONG OVERWEIGHT MEN WITH CHRONIC INSOMNIA SYMPTOMS

Higher morning fasting plasma NEFA level is associated with worse quality of sleep among overweight men with chronic insomnia symptoms

Plasma profile of hormones and energy metabolites in low and high producing periparturient Sahiwal cows during summer and winter season

In order to study the plasma hormonal and metabolic changes in Zebu (Sahiwal) cattle during summer and winter season, five each of periparturient high and low yielding cows were selected from Livestock Research Centre, ICAR-NDRI, Karnal. Blood samples were collected on days -45, -30, -15 (prior to parturition), 0 (day of parturition) and 15, 30, 45 (postpartum) during both the seasons and plasma was separated. Plasma cortisol levels were significantly higher on day of parturition and during postpartum period in both the groups during both the seasons. Plasma insulin levels were significantly (P less than 0.05) lower during summer in high yielder group. On the day of calving, plasma T3 and T4 levels were significantly (Pless than 0.05) lower in high yielders during both seasons. Plasma leptin levels were lower (Pless than 0.05) on day of parturition in high yielders than low yielders during both seasons. Plasma glucose levels were significantly lower (Pless than 0.05) on day of parturition and remained low during postpartum period in both groups during both seasons comparel to prepartum period. Plasma NEFA levels of both groups of cows were higher on the day of calving and remained higher during postpartum period over pre calving values. High yielder cows showed more deviation in stress markers viz. cortisol and NEFA than low yielder cows. Therefore, special attention should be given to feeding and management of the lactating animals (especially high yielding cows during summer) around parturition for sustained productivity and maintenance of homeostasis.

Liquid fructose in pregnancy exacerbates fructose-induced dyslipidemia in adult female offspring

Fructose intake from added sugars correlates with the epidemic rise in metabolic syndrome and related events. Nevertheless, consumption of beverages sweetened with fructose is not regulated in gestation. Previously, we found that maternal fructose intake produces in the progeny, when fetuses, impaired leptin signaling and hepatic steatosis and then impaired insulin signaling and hypoadiponectinemia in adult male rats. Interestingly, adult females from fructose-fed mothers did not exhibit any of these disturbances. However, we think that, actually, these animals keep a programmed phenotype hidden. Fed 240-day-old female progeny from control, fructose- and glucose-fed mothers were subjected for 3weeks to a fructose supplementation period (10% wt/vol in drinking water). Fructose intake provoked elevations in insulinemia and adiponectinemia in the female progeny independently of their maternal diet. In accordance, the hepatic mRNA levels of several insulin-responsive genes were similarly affected in the progeny after fructose intake. Interestingly, adult progeny of fructose-fed mothers displayed, in response to the fructose feeding, augmented plasma triglyceride and NEFA levels and hepatic steatosis versus the other two groups. In agreement, the expression and activity for carbohydrate response element binding protein (ChREBP), a lipogenic transcription factor, were higher after the fructose period in female descendants from fructose-fed mothers than in the other groups. Furthermore, liver fructokinase expression that has been indicated as one of those responsible for the deleterious effects of fructose ingestion was preferentially augmented in that group. Maternal fructose intake does influence the adult female offspring's response to liquid fructose and so exacerbates fructose-induced dyslipidemia and hepatic steatosis.

Plasma profile of hormones and energy metabolites during periparturient period in low and high producing Karan Fries (Holstein Friesian × Tharparkar) cows during different seasons

In order to find out the hormonal and metabolic profile during summer and winter season, five each of periparturient high and low yielding Karan Fries cows were selected from Livestock Research Centre (LRC) of ICAR-NDRI, Karnal. Blood samples were collected from both the group of animals on days (-45, -30, -15) of prepartum, 0 (expected day of calving) and on 15th, 30th and 45th day of postpartum during both the seasons. Plasma was separated by centrifuging the blood samples in the refrigerated centrifuge for energy metabolites and hormones. The plasma glucose levels were significantly lower on 0 day and remains lower upto 45th day of postpartum in both the groups and seasons compared to prepartum period (45 days). The plasma NEFA levels in high yielder group and during summer were higher on 15th day of postpartum compared to low yielders and during winter respectively. The plasma cortisol levels were significantly higher on the day of calving in high yielding group of Karan Fries cows compared to low yielding group animals . Plasma cortisol levels were significantly higher on the day of calving and remain higher during postpartum period (upto 45 days) in both groups and seasons compared to prepartum period. On the day of calving, plasma insulin, T3, T4 and leptin levels were significantly lower in high yielding group compared to low yielding group during both the seasons. The results of the present study clearly indicate more fluctuations in different stress markers in high yielding group compared to low yielding group during summer season. Although, both the groups of crossbred cows required protection during extreme climatic conditions, but high yielders group will require extra protection during the climate change scenario in future. Therefore, special care needs to be given to manage the high yielding animals during periparturient period to improve/maintain the productivity.

Fasting rapidly increases fatty acid oxidation in white adipose tissue (269.2)

Upregulating fatty acid oxidation in white adipose tissue in mice protects against diet‐induced obesity and excess plasma NEFA levels. At least part of this capacity results from the induction of brown‐like adipocytes within classical white depots, making it difficult to determine if white adipocytes contribute. Avian genomes lack a gene for uncoupling protein 1 and are devoid of brown adipocytes, making them a useful model in which to study lipid metabolism in white adipocytes. We recently reported that a brief (5 hr) period of fasting upregulated expression of genes involved in mitochondrial and peroxisomal fatty acid oxidation in white adipose tissue of broiler chickens. The objective of this study was to determine if the effects on gene expression manifested in increased rates of fatty acid oxidation. Abdominal adipose tissue was collected from 21 day‐old broiler chicks that fasted for 3.5, 5 or 7 hrs, or fed ad libitum. Fatty acid oxidation was determined by measuring and summing 14CO2 production and 14C‐labeled acid‐soluble metabolites from the oxidation of [1‐14C]palmitic acid. Citrate synthase activity was measured spectrophotometrically. Fasting induced a progressive increase in complete oxidation which was significantly different from controls in the 5.5 hr (p=0.0037) and 7 hr (p=0.0021) groups (1.14, 1.2, 1.49 and 1.95 nmol/mg protein/hr; control, 3.5, 5 and 7 hrs, respectively). Citrate synthase activity increased significantly after 7 hrs of fasting. Fasting did not significantly alter the production of acid soluble metabolites, an index of incomplete fatty acid oxidation. These results confirm that fasting rapidly increases fatty acid oxidation in white adipose tissue by upregulating the transcription of key regulatory enzymes and proteins. Identifying the underlying mechanism may provide new therapeutic targets through which to increase fatty acid oxidation in situ and protect against obesity and the detrimental effects of excess NEFA on adipocyte insulin sensitivity.

Effect of Peripheral 5-HT on Glucose and Lipid Metabolism in Wether Sheep

In mice, peripheral 5-HT induces an increase in the plasma concentrations of glucose, insulin and bile acids, and a decrease in plasma triglyceride, NEFA and cholesterol concentrations. However, given the unique characteristics of the metabolism of ruminants relative to monogastric animals, the physiological role of peripheral 5-HT on glucose and lipid metabolism in sheep remains to be established. Therefore, in this study, we investigated the effect of 5-HT on the circulating concentrations of metabolites and insulin using five 5-HT receptor (5HTR) antagonists in sheep. After fasting for 24 h, sheep were intravenously injected with 5-HT, following which-, plasma glucose, insulin, triglyceride and NEFA concentrations were significantly elevated. In contrast, 5-HT did not affect the plasma cholesterol concentration, and it induced a decrease in bile acid concentrations. Increases in plasma glucose and insulin concentrations induced by 5-HT were attenuated by pre-treatment with Methysergide, a 5HTR 1, 2 and 7 antagonist. Additionally, decreased plasma bile acid concentrations induced by 5-HT were blocked by pre-treatment with Ketanserin, a 5HTR 2A antagonist. However, none of the 5HTR antagonists inhibited the increase in plasma triglyceride and NEFA levels induced by 5-HT. On the other hand, mRNA expressions of 5HTR1D and 1E were observed in the liver, pancreas and skeletal muscle. These results suggest that there are a number of differences in the physiological functions of peripheral 5-HT with respect to lipid metabolism between mice and sheep, though its effect on glucose metabolism appears to be similar between these species.