IGF-I Concentrations Research Articles

Metabolic Profile of Growing Immune- and Surgically Castrated Iberian Pigs Fed Diets of Different Amino Acid Concentration.

The purpose of the current study was to further characterize the performance and nitrogen retention differences previously observed between immunocastrated (IC) and surgically castrated (SC) pure Iberian pigs. Fifty-four pigs were used (three sexes: IC males, IC females and SC males), fed three isoenergetic diets (160, 140 and 120 g CP/kg DM; six pigs/treatment combination) from 40 kg BW until slaughter (105 kg BW). Plasmatic post-absorptive metabolites and hormones, and backfat tissue composition were determined. The IC males showed a trend towards higher plasmatic creatinine (p = 0.06) and IGF-1 concentrations than SC males and IC females (p < 0.001). SC males showed a higher predisposition to carcass fatness and insulin resistance compared to IC males. Plasmatic isoleucine concentration was higher in IC and SC males compared to IC females (p < 0.01), and valine was greater in IC males compared to the rest of the pigs (p < 0.001). Total branched-chain amino acids (AA) were greater in IC males than in IC females (p < 0.01). Total plasmatic essential AA concentrations tended to be greater in IC males (p = 0.09). The present results support the increased performance and nitrogen retention capacity previously observed in IC male Iberian pigs compared to SC males and IC females, which can be attributed to increased anabolic capacity related with lean growth in Iberian IC males.

Delayed skeletal development and IGF-1 deficiency in a mouse model of lysinuric protein intolerance.

SLC7A7 deficiency, or lysinuric protein intolerance (LPI), causes loss of function of the y+LAT1 transporter critical for efflux of arginine, lysine and ornithine in certain cells. LPI is characterized by urea cycle dysfunction, renal disease, immune dysregulation, growth failure, delayed bone age, and osteoporosis. We previously reported that Slc7a7 knockout mice (C57BL/6 x 129/SvEv F2) recapitulate LPI phenotypes, including growth failure. Our main objective was to characterize the skeletal phenotype in these mice. Compared to wild type littermates, juvenile Slc7a7 knockout mice demonstrated 70% lower body weights, 87% lower plasma IGF-1 concentrations, and delayed skeletal development. Because poor survival prevents evaluation of mature knockout mice, we generated a conditional Slc7a7 deletion in mature osteoblasts or mesenchymal cells of the osteo-chondroprogenitor lineage, butno differences in bone architecture were observed. Overall, global Slc7a7 deficiency caused growth failure with low plasma IGF-1 concentrations and delayed skeletal development, but Slc7a7 deficiency in the osteoblastic lineage was not a major contributor to these phenotypes. Future studies utilizing additional tissue-specific Slc7a7 knockout models may help dissect cell autonomous and non-cell autonomous mechanisms underlying phenotypes in LPI.

Acute Physiological Effects of Drop Set on IGF and GH in the Quadriceps Femoris Among Males in Kakamega County, Kenya

Background: Resistance training (RT) for muscle growth (hypertrophy training – HT) theoretically optimizes the mechanical tension placed on the working muscle, which may be key to activating hypertrophic mechanisms. After prolonged HT, specialized weightlifting techniques like drop set training (DS) – or lifting progressively reduced loads without recovery – may help overcome plateaus in strength and re-stimulate hypertrophy, but physiological evidence to potentially support this hypothesis or the efficacy of implementing an acute drop set protocol in comparison to maintaining a standard hypertrophy training program is lacking. Objective: This objective of this study was to assess the levels of plasma growth hormone, and IGF during drop set and concentric exercises. Methods: The study used a randomized controlled, counterbalanced, repeated measures design. A repeated measures design was used to minimize the inter-individual variability of the hypertrophic response to resistance training. Thirty young males participated in a randomized, counterbalanced, within-subjects design, a DS protocol (4 sets, 4 loads/set, 75-30% 1RM, minimal recovery between loads, 3-minute recovery intervals between sets) and, separated by at least 7 days, a HT protocol (4 sets, 75% 1RM, 3-minute recovery intervals between sets). Data was analyzed using a 2 (Training Type: DS, HT, levels of quadriceps muscle hypertrophy) ´ 2 (Time: pre-exercise, post-exercise) repeated measures ANOVA to test the differences in concentrations of IGF-1 and GH during DS and HT at the specified time points. Results: The study found that there was a significant difference in IGF 1 levels before and after the exercise for both groups (Drop set and concentric exercise), with a p-value of .007. The interaction effect between the within-subjects factor (IGF 1 pre and post) and group was also significant. The results showed that there was a significant difference in GH levels before and after the exercise for both groups (Drop set and concentric exercise), with a p-value of &lt; .001. For the Drop set group, GH pre was also significantly lower than GH post. It can be concluded that both the drop set and concentric exercise techniques have an impact on the levels of IGF 1, and GH in the quadriceps femoris. The study recommends that physical trainers and fitness professionals should consider using the Drop set exercise technique in their training programs for clients who are looking to improve their performance.

Artificial shade as a heat abatement strategy to grazing beef cow-calf pairs in a subtropical climate.

Grazing livestock in subtropical and tropical regions are susceptible to prolonged exposition to periods of extreme environmental conditions (i.e., temperature and humidity) that can trigger heat stress (HS). Currently, there is limited information on the effects of HS in the cow-calf sector globally, including in the southern U.S., as well as on mitigation strategies that could be implemented to improve animal well-being and performance. This study evaluated the impact of artificial shade (SHADE vs. NO SHADE) and breed (ANGUS vs. BRANGUS) on performance of pregnant-lactating cows, nursing heifers, and their subsequent offspring. Twenty-four Angus and 24 Brangus black-hided cows [579 ± 8 kg body weight (BW); approximately 85 d of gestation] and their nursing heifers (approximately 174 d of age) were randomly allocated to 12 'Pensacola' bahiagrass pastures (Paspalum notatum Flüggé; 1.3 ha, n = 4 pairs/pasture), with or without access to artificial shade [NO SHADE BRANGUS (NSB), NO SHADE ANGUS (NSA), SHADE BRANGUS (SB), and SHADE ANGUS (SA)] for 56 d that anticipated weaning during the summer season in Florida. Body condition score (BCS) of cows, blood samples, and BW of cow-calf pairs were obtained every 14 d during the 56-d experimental period until weaning. Following weaning (d 56), treatments were ceased, and cows and weaned heifers were managed alike. Weaned heifers were randomly allocated to 4 pens (n = 12/pen) equipped with GrowSafe feed bunks for 14 d to assess stress responses during weaning via plasma haptoglobin. An effect of SHADE × BREED interaction was detected for cow ADG, BW change, final BW, and final BCS, where SB had the greatest ADG, BW change, final BW, and final BCS. On d 14, SA cows had the greatest concentrations of insulin whereas on d 28 NSB had the lowest concentrations, NSA the greatest, and SA and SB being intermediate. On d 56, SA tended to have the greatest plasma insulin concentrations and SB the lowest. Weight gain per area (kg/ha) tended to be 11.4 kg/ha greater in SHADE vs. NO SHADE pastures. Pre-weaning calf ADG tended to be 0.14 kg greater for SHADE vs. NO SHADE calves. Weaning weight and BW at 14-d post-weaning were lesser for NSB vs. NSA, SA, and SB, whereas no differences in postweaning ADG or haptoglobin were observed. Effects of SHADE × BREED × day interaction was detected on plasma concentrations of IGF-1, in which NSA heifers had the lowest concentrations on weaning day. Gestation length was greater for SHADE vs. NO SHADE cows, but with no impacts on subsequent calf birth and weaning weight. In summary, providing artificial shade to pregnant-lactating beef cows increased body weight gain of nursing heifers and Brangus cows, while no impact on Angus dams were observed. The provision of artificial shade during the first trimester of gestation did not alter growth performance of the subsequent offspring at birth and weaning even though gestation length was longer.

Insulin growth factor axis and cardio-renal risk in diabetic kidney disease: an analysis from the CREDENCE trial

BackgroundThe insulin-like growth factors (IGF) play a crucial role in regulating cellular proliferation, apoptosis, and key metabolic pathways. The ratio of IGF-1 to IGF binding protein-3 (IGFBP-3) is an important factor in determining IGF-1 bioactivity. We sought to investigate the association of IGF-1 and IGFBP-3 with cardio-renal outcomes among persons with type 2 diabetes.MethodsSamples were available from 2627 individuals with type 2 diabetes and chronic kidney disease that were randomized to receive canagliflozin or placebo and were followed up for incident cardio-renal events. Primary outcome was defined as a composite of end-stage kidney disease, doubling of the serum creatinine level, or renal/cardiovascular death. IGF-1 and IGFBP-3 were measured at baseline, Year-1 and Year-3. Elevated IGF-1 level was defined according to age-specific cutoffs. Cox proportional hazard regression was used to investigate the association between IGF-1 level, IGFBP-3, and the ratio of IGF-1/IGFBP-3 with clinical outcomes.ResultsElevated IGF-1 was associated with lower glomerular filtration rate at baseline. Treatment with canagliflozin did not significantly change IGF-1 and IGFBP-3 concentrations by 3 years (p-value > 0.05). In multivariable models, elevated IGF-1 (above vs below age-specific cutoffs) was associated with the primary composite outcome (incidence rate:17.8% vs. 12.7% with a hazard ratio [HR]: 1.52; 95% confidence interval CI 1.09–2.13;P: 0.01), renal composite outcome (HR: 1.65; 95% CI 1.14–2.41; P: 0.01), and all-cause mortality (HR: 1.52; 95% CI 1.00–2.32; P; 0.05). Elevations in log IGFBP-3 did not associate with any clinical outcomes. Increase in log IGF-1/IGFBP-3 ratio was also associated with a higher risk of the primary composite outcome (HR per unit increase: 1.57; 95% CI 1.09–2.26; P; 0.01).ConclusionsThese results further suggest potential importance of IGF biology in the risk for cardio-renal outcomes in type 2 diabetes. SGLT2 inhibition has no impact on the biology of IGF despite its significant influence on outcomes.Trial registration: CREDENCE; ClinicalTrials.gov Identifier: NCT02065791.

Evaluation of an onco-diet on body composition and inflammatory status of dogs with mammary tumor-Pilot study.

A high-protein hypercaloric diet enriched with glutamine and omega-3 polyunsaturated fatty acids was called an onco-diet. The goal was to verify the modulation of the inflammatory response and body composition of female dogs with mammary tumor after mastectomy, during onco-diet consumption, using a randomized, double-blinded, clinical trial. Six bitches (average age of 8.6 years) were allocated into Control Group-diet without glutamine, EPA and DHA supplementation; and six bitches (10.0 years) were allocated into Test-diet enriched with glutamine and omega-3. Serum measurements of TNF-α, IL-6, IL-10, IGF-1, C-reactive protein and determination of body composition were performed at pre- and post-surgical times. Statistical tests were used to compare the nutrient intake and dietary effects on inflammatory variables between the diets. No differences in concentrations of different cytokines (p>0.05) and C-reactive protein (CRP) (p = 0.51) were observed between the groups. The test group had a higher concentration of IGF-1 (p<0.05), higher percentage of muscle mass (p<0.01) and lower body fat (p<0.01), but the difference was present from initial and throughout the study. Onco-diet, enriched with glutamine and omega-3, in the amounts evaluated in this study, was not sufficient to modulate the inflammation and body composition of female dogs with mammary tumors submitted to unilateral mastectomy.

Short communication: The biological value of transition milk: analyses of immunoglobulin G, IGF-I and lactoferrin in primiparous and multiparous dairy cows.

Colostrum (the first mammary gland secretion after calving) is known to contain high concentrations of nutrients as well as bioactive substances (including immunoglobulins, growth factors, and antimicrobial factors) to ensure neonatal survival. Due to its immunomodulatory, antibacterial, and antiviral activities, bovine colostrum has been used not only in calves but also in the prevention and treatment of human gastrointestinal and respiratory infections. Transition milk is the mammary secretion from the second milking to the sixth, which may contain these bioactive compounds to a lesser extent. The objective of the present study was to measure IGF-I, immunoglobulin G (IgG), and lactoferrin (LTF) concentrations in colostrum and transition milk of primiparous and multiparous cows to further assess its potential use in veterinary and nutraceutical applications. The results demonstrated that the concentrations of these three bioactive molecules decrease from the first milking to the tenth. Concentrations of IGF-I and LTF were greater in multiparous than in primiparous cows. Also, lactation number interacted with milking number in IGF-I, since primiparous cows had a smoother decline of IGF-I concentrations than multiparous ones. Overall, transition milk from the second milking showed a 46% decrease in the analysed colostrum bioactive molecules. Therefore, further studies are needed to apply this knowledge in neonate farm management practices or in developing pharmaceutical supplements from farm surpluses.

FTO Gene Polymorphisms and Their Roles in Acromegaly.

The major causes of both morbidity and mortality in patients with acromegaly are cardiovascular diseases (CVDs). The polymorphisms of the fat mass and obesity-associated gene (FTO) are associated with obesity, as well as with an increased risk of CVDs. The aim of the study was to determine the relationship of risk alleles of four FTO gene polymorphisms with selected parameters of lipid and glucose metabolism as well as with IGF-1 and GH levels in the group of patients with acromegaly compared to the control group. The study group consisted of 104 patients with acromegaly and 64 healthy subjects constituting the control group. In the whole acromegaly group, the data reveal that the homozygous for risk allele carriers (rs1421085, rs9930506, rs9939609) as well as carriers of only one risk allele have lower IGF-1 concentrations. In the well-controlled acromegaly group, the homozygous for three risk allele carriers of FTO gene polymorphisms have lower HDL cholesterol concentration (rs1121980, rs1421085, rs993609). In the cured acromegaly group, homozygous risk allele carriers rs9930506 tend to have higher levels of total cholesterol and LDL cholesterol. These associations are not observed in the control group. Conclusion: there is an association between FTO gene polymorphisms and the metabolism of lipids, suggesting that the FTO gene may be associated with higher CVD risk in patients with acromegaly. In addition, there is an association between FTO gene polymorphisms and IGF-1, implying that FTO gene may influence/modify IGF-1 synthesis. Further investigation on a larger scale is required to provide more precise evidence.

Difficulties in Interpreting IGF-1 Levels in Short Stature Children Born Small for Gestational Age (SGA) Treated with Recombinant Human Growth Hormone (rhGH) Based on Data from Six Clinical Centers in Poland

The assessment of IGF-1 concentrations is one of the parameters used for evaluating response to rhGH treatment. An increase in IGF-1 concentration positively correlates with growth improvement, whereas IGF-1 concentrations significantly above the reference range may increase the risk of possible side effects. The aim of this study was to evaluate the IGF-1 local reference ranges for the rhGH treatment centers concerned and to compare these values with the population reference ranges. A retrospective analysis was conducted on auxological data from 229 SGA patients who received rhGH treatment between 2016 and 2020 at six university clinical centers in Poland. The IGF-1 levels were assessed at baseline, after 12 and 24 months, and compared to the reference ranges provided by the local laboratory and to the population reference ranges. After 12 months, 56 patients (24%) presented IGF-1 values &gt; 97th percentile for the local reference range, whereas only 8 (3.5%) did so using the population reference ranges; p &lt; 0.001. After 24 months of treatment, the values were: 47 (33%) &gt; 97th percentile by local vs. 6 (4.2%) by population standards; p &lt; 0.001. Thirty-nine patients had rhGH dose reduced after 12 months, of whom twelve (25%) had IGF-1 &gt; 97th percentile according to the local reference ranges and five (13%) &gt; 97th percentile for the population. Our data suggest that different methods used to determine IGF-1 concentration and the different IGF-1 reference ranges result in a significant proportion of rhGH-treated children with elevated IGF-1 concentration and experiencing dose reductions, which may negatively affect growth rate.

Dietary intake of xylose impacts the transcriptome and proteome of tissues involved in xylose metabolism in swine

Xylose is a primary component of arabinoxylan in swine diets. As arabinoxylan is a significant component of fiber, and fiber is generally rising in practical pig diets globally, the study of arabinoxylan and xylose is of increasing interest. However, the mechanisms by which free xylose may be absorbed and the pathways impacted by xylose have yet to be elucidated in pigs. The objective of this study was to determine the impact of xylose supplementation on gene expression and protein abundance in jejunum, kidney, liver, and muscle tissues which have previously been identified as possible sites of xylose absorption or metabolism. This study aimed to expand the preliminary understanding of dietary xylose metabolism and utilization in pigs. One study, replicated twice with 24 crossbred gilts, was used to assess two dietary treatments: a xylose-free (0%) control and 8% D-xylose. The impact of xylose on growth was monitored by measuring initial and final body weight, serum IGF-1, and liver glycogen concentrations. The rate and efficiency of weight gain were reduced on the xylose diet but not to a level that would occur if xylose was not used at all; the detection of xylose systemically further supports this conclusion. This study confirmed that pigs can utilize dietary xylose. To determine the impact of xylose on tissue metabolism, samples were collected from all four tissues for gene expression analysis by RNA-sequencing, and kidney and liver samples were subjected to proteomic analysis using 2D-DIGE and mass spectrometry. The majority of differentially expressed (DE) genes were identified in the kidney samples (n = 157), with a few identified in the jejunum (n = 16), liver (n = 1), and muscle (n = 20) samples. The DE genes in the kidney were mainly identified as being involved in lipid biosynthesis and fatty acid metabolism. Proteomic results corroborated these findings. Although the inclusion of xylose in a diet at practical levels is shown to impact energy metabolic processes, it has been confirmed that this five-carbon sugar can support levels of growth only slightly below those of glucose, a six-carbon sugar that is more commonly utilized as an energy source in pig diets.

Muscle hypertrophy training does not suppress the GH/IGF axis in young adult males.

This study aimed to analyze the expression of the IGF type-1 receptor gene (IGF-1r) and IGF-I, GH, testosterone, and IGFBP-3 concentrations in young people subjected to 10weeks of muscle hypertrophy training. IGF-1r expression, serum concentrations of IGF-I, IGFBP-3, GH, and total testosterone, as well as body composition, fat percentage, and body mass index, were determined for 22 healthy young males at three moments of resistance training (first, fifth, and tenth week of training). Throughout the 10weeks of training, a reduction was observed in the relative expression of the IGF-1r gene (2-ΔΔCT) and an increase in IGF-I and GH concentrations. A reduction in total testosterone concentrations was detected during the recovery period in the fifth week. The IGFBP-3 concentrations did not change throughout the training. The resistance training protocol prescribed for muscle hypertrophy did not suppress the GH-IGF-I axis, but it did cause alterations in IGF-1r gene expression and in IGF-I kinetics compatible with increased IGF bioactivity.

Hypoxia Preconditioned Serum (HPS) Promotes Proliferation and Chondrogenic Phenotype of Chondrocytes In Vitro.

Autologous chondrocyte implantation (ACI) for the treatment of articular cartilage defects remains challenging in terms of maintaining chondrogenic phenotype during in vitro chondrocyte expansion. Growth factor supplementation has been found supportive in improving ACI outcomes by promoting chondrocyte redifferentiation. Here, we analysed the chondrogenic growth factor concentrations in the human blood-derived secretome of Hypoxia Preconditioned Serum (HPS) and assessed the effect of HPS-10% and HPS-40% on human articular chondrocytes from osteoarthritic cartilage at different time points compared to normal fresh serum (NS-10% and NS-40%) and FCS-10% culture conditions. In HPS, the concentrations of TGF-beta1, IGF-1, bFGF, PDGF-BB and G-CSF were found to be higher than in NS. Chondrocyte proliferation was promoted with higher doses of HPS (HPS-40% vs. HPS-10%) and longer stimulation (4 vs. 2 days) compared to FCS-10%. On day 4, immunostaining of the HPS-10%-treated chondrocytes showed increased levels of collagen type II compared to the other conditions. The promotion of the chondrogenic phenotype was validated with quantitative real-time PCR for the expression of collagen type II (COL2A1), collagen type I (COL1A1), SOX9 and matrix metalloproteinase 13 (MMP13). We demonstrated the highest differentiation index (COL2A1/COL1A1) in HPS-10%-treated chondrocytes on day 4. In parallel, the expression of differentiation marker SOX9 was elevated on day 4, with HPS-10% higher than NS-10/40% and FCS-10%. The expression of the cartilage remodelling marker MMP13 was comparable across all culture conditions. These findings implicate the potential of HPS-10% to improve conventional FCS-based ACI culture protocols by promoting the proliferation and chondrogenic phenotype of chondrocytes during in vitro expansion.

Analysis of Nephrolithiasis Treatment in Highest Reference Hospital-Occurrence of Acromegaly in the Study Group.

Urolithiasis is one of the most common diseases of the urinary system, the incidence of which is assumed to be up to 100,000 cases per million (10% of the population). The cause of it is dysregulation of renal urine excretion. Acromegaly is a very rare endocrine disorder that causes a somatotropic pituitary adenoma producing higher amounts of growth hormone. It occurs approximately in 80 cases per million (about 0.008% of the population). One of the acromegaly complications may be urolithiasis. Clinical and laboratory results of 2289 patients hospitalized for nephrolithiasis in the highest reference hospital were retrospectively analyzed, distinguishing a subgroup of patients with acromegaly. Statistical analysis was performed to compare the prevalence of the disease in the analyzed subgroup with the epidemiological results available in up-to-date literature. The distribution of nephrolithiasis treatment was definitely in favor of non-invasive and minimally invasive treatment. The methods used were as follows: ESWL (61.82%), USRL (30.62%), RIRS (4.15%), PCNL (3.1%), and pyelolithotomy (0.31%). Such a distribution limited the potential complications of the procedures while maintaining the high effectiveness of the treatment. Among two thousand two hundred and eighty-nine patients with urolithiasis, two were diagnosed with acromegaly before the nephrological and urological treatment, and seven were diagnosed de novo. Patients with acromegaly required a higher percentage of open surgeries (including nephrectomy) and also had a higher rate of kidney stones recurrence. The concentration of IGF-1 in patients with newly diagnosed acromegaly was similar to those treated with somatostatin analogs (SSA) due to incomplete transsphenoidal pituitary surgery. In the population of patients with urolithiasis requiring hospitalization and interventional treatment compared to the general population, the prevalence of acromegaly was almost 50-fold higher (p = 0.025). Acromegaly itself increases the risk of urolithiasis.

Influence of lactational status of the surrogate mare during early pregnancy on inflammatory markers in subsequently born foals

Nutrition during pregnancy has a significant impact on the offspring and affects health, growth and metabolism in several species, including equines. Studies have associated orthopedic problems in foals, such as osteochondritis dissecans (OCD), with diet of the broodmare during pregnancy resulting in high glucose concentrations, causing suppression of the central regulation of growth hormone (GH) secretion and subsequent disruption of the GH/IGF-1 (insulin-like growth factor-1) axis. It is very common to use non-lactating mares as embryo recipients, however little is known about the effect of lactational status on pregnant mare metabolism and the effect on the resulting embryo, fetus and the offspring's metabolism and development. Our study aimed to compare inflammatory cytokines, osteocalcin and IGF-1 in foals born from lactating recipient mares (LM; n=7) and non-lactating recipient mares (NLM; n=5) from days 1-28 after birth. Twelve healthy Mangalarga Paulista mares aged 5 to 15 years of age were used. Twelve foals, eight males and four females, born by eutocia were evaluated. Recipient LMs were lactating from the day of ovulation, until a maximum of 170 days of pregnancy (124 to 170). Foal evaluations were performed at birth (D1) and at 7, 14, 21 and 28 days of age (D7, D14, D21 and D28). Leptin (ng/mL), adiponectin (µg/mL), resistin (ng/mL) analyses were performed using ELISA, and interleukin6 (IL6; pg/mL), interleukin 10 (IL10; pg/mL), tumor necrosis factor (TNFα; pg/mL), osteocalcin (ng/mL) and IGF-1 (ng/mL) were evaluated using immunoassay kits. We used a factorial arrangement between group (LM x NLM) and time (D1, D7, D14, D21 and D28). The results are the mean and standard error of the mean. There was no significant interaction in any of the variables. Concentrations of IGF-1, IL6, IL10 and TNFα were higher in the NLM group (IGF1: 29.48±3.82 vs 176.53±65.8, p=0.0002; IL6:9.89±0.74 vs 13.57±1.33, p=0.01; IL10: 75.37±3.89 vs 100.75±8.84, p=0.0006 and TNFα: 8.08±1.08 vs 12.89±1.75, p<0.001). Only in IL10 concentration, there was a difference over time (D1: 114.11±1.04; D7: 72.08±8.13; D14: 12±6.96; D21: 72.98±5.25 and D28:100.44±9.25; p<0.001). Osteocalcin correlated positively with leptin (p<0.05; r=0.27). In this study, the recipient mares’ lactational status during the first trimester of pregnancy influenced concentrations of inflammatory markers in the subsequently born foal up to 28 days of life, with higher concentrations of IGF-1, IL6, IL10 and TNFα than in foals born from non-lactating recipient mares. This raises an important discussion on the impact of lactational status of the recipient dam on the future of her offspring. Acknowledgements: FAPESP (2017/05425-0 and 2020/10260-3) and CAPES

Impact of Chorionic Somatomammotropin In Vivo RNA Interference Phenotype on Uteroplacental Expression of the IGF Axis.

While fetal growth is dependent on many factors, optimal placental function is a prerequisite for a normal pregnancy outcome. The majority of fetal growth-restricted (FGR) pregnancies result from placental insufficiency (PI). The insulin-like growth factors (IGF1 and IGF2) stimulate fetal growth and placental development and function. Previously, we demonstrated that in vivo RNA interference (RNAi) of the placental hormone, chorionic somatomammotropin (CSH), resulted in two phenotypes. One phenotype exhibits significant placental and fetal growth restriction (PI-FGR), impaired placental nutrient transport, and significant reductions in umbilical insulin and IGF1. The other phenotype does not exhibit statistically significant changes in placental or fetal growth (non-FGR). It was our objective to further characterize these two phenotypes by determining the impact of CSH RNAi on the placental (maternal caruncle and fetal cotyledon) expression of the IGF axis. The trophectoderm of hatched blastocysts (9 days of gestation, dGA) were infected with a lentivirus expressing either a non-targeting sequence (NTS RNAi) control or CSH-specific shRNA (CSH RNAi) prior to embryo transfer into synchronized recipient ewes. At ≈125 dGA, pregnancies were fitted with vascular catheters to undergo steady-state metabolic studies. Nutrient uptakes were determined, and tissues were harvested at necropsy. In both CSH RNAi non-FGR and PI-FGR pregnancies, uterine blood flow was significantly reduced (p ≤ 0.05), while umbilical blood flow (p ≤ 0.01), both uterine and umbilical glucose and oxygen uptakes (p ≤ 0.05), and umbilical concentrations of insulin and IGF1 (p ≤ 0.05) were reduced in CSH RNAi PI-FGR pregnancies. Fetal cotyledon IGF1 mRNA concentration was reduced (p ≤ 0.05) in CSH RNAi PI-FGR pregnancies, whereas neither IGF1 nor IGF2 mRNA concentrations were impacted in the maternal caruncles, and either placental tissue in the non-FGR pregnancies. Fetal cotyledon IGF1R and IGF2R mRNA concentrations were not impacted for either phenotype, yet IGF2R was increased (p ≤ 0.01) in the maternal caruncles of CSH RNAi PI-FGR pregnancies. For the IGF binding proteins (IGFBP1, IGFBP2, IGFBP3), only IGFBP2 mRNA concentrations were impacted, with elevated IGFBP2 mRNA in both the fetal cotyledon (p ≤ 0.01) and maternal caruncle (p = 0.08) of CSH RNAi non-FGR pregnancies. These data support the importance of IGF1 in placental growth and function but may also implicate IGFBP2 in salvaging placental growth in non-FGR pregnancies.

Insulin like growth factor I plasma concentration assessment during the luteal phase in pregnant and non pregnant llamas

This study aimed to assess the temporal association between plasma Insulin like growth factor I (IGF1) and progesterone (P4) concentration during the luteal phase in pregnant and non-pregnant llamas. On Day 0, sixteen llamas were induced to ovulate either by mating (n = 10) or by a single dose of buserelin (n = 6). All llamas were examined by transrectal ultrasonography every other day from Day 6 until Day 14 post-induction of ovulation to assess corpus luteum diameter. Blood samples were collected every other day from Day 0 until Day 14 post-induction of ovulation to evaluate plasma P4 and IGF1 concentrations. Plasma IGF1 concentration was between 109 and 499 ng/ml, without significant differences between groups (pregnant, mated non-pregnant and induced to ovulate by buserelin). No significant differences were observed in plasma IGF1 concentration between follicular and luteal phase, nor between the different days of the luteal phase. There was no correlation between plasma IGF1 and P4 concentration or corpus luteum diameter. In conclusion, mean plasma IGF1 concentration did not significantly change along the luteal phase and was similar between pregnant and non-pregnant llamas; without showing an association with corpus luteum function.

Nutritional status affects Igf1 regulation of skeletal muscle myogenesis, myostatin, and myofibrillar protein degradation pathways in gopher rockfish (Sebastes carnatus)

Insulin-like growth factor-1 (Igf1) regulates skeletal muscle growth in fishes by increasing protein synthesis and promoting muscle hypertrophy. When fish experience periods of insufficient food intake, they undergo slower muscle growth or even muscle wasting, and those changes emerge in part from nutritional modulation of Igf1 signaling. Here, we examined how food deprivation (fasting) affects Igf1 regulation of liver and skeletal muscle gene expression in gopher rockfish (Sebastes carnatus), a nearshore rockfish of importance for commercial and recreational fisheries in the northeastern Pacific Ocean, to understand how food limitation impacts Igf regulation of muscle growth pathways. Rockfish were either fed or fasted for 14 d, after which a subset of fish from each group was treated with recombinant Igf1 from sea bream (Sparus aurata). Fish that were fasted lost body mass and had lower body condition, reduced hepatosomatic index, and lower plasma Igf1 concentrations, as well as a decreased abundance of igf1 gene transcripts in the liver, increased hepatic mRNAs for Igf binding proteins igfbp1a, igfbp1b, and igfbp3a, and decreased mRNA abundances for igfbp2b and a putative Igf acid labile subunit (igfals) gene. In skeletal muscle, fasted fish showed a reduced abundance of intramuscular igf1 mRNAs but elevated gene transcripts encoding Igf1 receptors A (igf1ra) and B (igf1rb), which also showed downregulation by Igf1. Fasting increased skeletal muscle mRNAs for myogenin and myostatin1, as well as ubiquitin ligase F-box only protein 32 (fbxo32) and muscle RING-finger protein-1 (murf1) genes involved in muscle atrophy, while concurrently downregulating mRNAs for myoblast determination protein 2 (myod2), myostatin2, and myogenic factors 5 (myf5) and 6 (myf6 encoding Mrf4). Treatment with Igf1 downregulated muscle myostatin1 and fbxo32 under both feeding conditions, but showed feeding-dependent effects on murf1, myf5, and myf6/Mrf4 gene expression indicating that Igf1 effects on muscle growth and atrophy pathways is contingent on recent food consumption experience.

Physiological traits of newborn piglets associated with colostrum intake, neonatal survival and preweaning growth

Colostrum intake, which is critical for piglet survival after birth and growth up to weaning, greatly depends on piglet weight and vitality at birth. Our aim was to identify a set of biological variables explaining individual variations in colostrum intake, preweaning growth and risk of dying. Farrowing traits, morphological traits and colostrum intake were determined for 504 piglets born alive from 37 Landrace × Large White sows. A subset of 203 of these piglets was used to measure plasma neonatal concentrations of metabolites and hormones in blood collected from the umbilical cord at birth. From univariate analyses, we established that colostrum intake was positively associated with plasma neonatal concentrations of IGF-I, albumin, thyroid hormones (P < 0.001), and non-esterified fatty acids (P < 0.05), and was negatively associated with concentrations of lactate (P < 0.001). In a multivariable analysis, the variables explaining the variation in colostrum intake were piglet birth weight and rectal temperature 1 h after birth (positive effect, P < 0.001), time of birth after the onset of parturition, and fructose plasma concentrations at birth (negative effects, P < 0.001 and P < 0.05, respectively). Piglets that died within 3 days after birth had lower neonatal concentrations of albumin (P < 0.001), IGF-I and thyroxine (P < 0.01) than surviving piglets. Preweaning growth was positively associated with neonatal concentrations of IGF-I, thyroxine (P < 0.001), albumin and insulin (P < 0.05). Cortisol and glucose concentrations at birth were not related to colostrum intake, neonatal survival or preweaning growth. Multivariable analyses confirmed that colostrum intake was the predominant factor influencing piglet survival within 3 days after birth and preweaning growth. These results provide physiological indicators of piglet colostrum intake, besides birth weight. They also confirm the impact of time of birth during farrowing on colostrum intake and the crucial importance of physiological maturity at birth for postnatal adaptation.

Effect of growth rates on hormonal and pubertal status in Nellore heifers early weaned.

This study aimed to determine the effect of growth rates on the hormonal status and puberty onset. Forty-eight Nellore heifers were weaned at 3.0 ± 0.1 (means ± standard error of the mean) months old were blocked according to body weight at weaning (84 ± 2 kg) and randomly assigned to treatments. The treatments were arranged in 2 × 2 factorial according to the feeding program. The first program was high (H; 0.79 kg/day) or control (C; 0.45 kg/day) average daily gain (ADG) from 3rd to 7th month of age (growing phase I). The second program was also high (H; 0.70 kg/day) or control (C; 0.50 kg/day) ADG from the 7th month until puberty (growing phase II), resulting in four treatments: HH (n = 13), HC (n = 10), CH (n = 13), and CC (n = 12). To achieve desired gains, heifers in high ADG program were fed ad libitum dry matter intake (DMI), and the control group was offered around 50% of ad libitum DMI of high group. All heifers received a diet with similar composition. Puberty was assessed weekly by ultrasound examination, and the largest follicle diameter was evaluated every month. Blood samples were collected to quantify leptin, insulin growth factor-1 (IGF1) and luteinizing hormone (LH). At 7 months of age, heifers in high ADG were 35 kg heavier than the control. Heifers in the HH had greater DMI compared with CH in phase II. The puberty rate at 19 months old was greater in the HH treatment (84%) than in the CC (23%), but there was no difference between HC (60%) and CH (50%) treatments. Heifers from HH treatment had greater serum leptin concentration than others at 13 months old, and serum leptin was greater in HH compared with CH and CC at 18 months old. High heifers in phase I had greater serum IGF1 concentration than the control. In addition, HH heifers had a greater diameter of the largest follicle than CC. There was no interaction between phases and age in any variable relative to the LH profile. However, the heifers' age was the main factor that increased the frequency of LH pulse. In conclusion, increasing ADG was associated with greater ADG, serum leptin and IGF-1 concentration, and puberty onset; however, LH concentration was affected mainly by age of the animal. The increasing growth rate at younger age made heifers more efficient.

Physiological and physical performance changes during a 20-day winter military training course and its subsequent 10-day recovery period

ABSTRACT The present study investigated physiological, mental and physical performance changes during a 20-day winter military training course and the following 10-day recovery period. Fifty-eight (age 19 ± 1 years, height 182 ± 6 cm, body mass 78.5 ± 7.2 kg) male soldiers volunteered. Body composition, serum biomarker levels and performance tests were measured four times during the study. In addition, questionnaires were collected daily for subjective stress and rate of perceived exertion. The course induced significant declines in body (−3.9%, p < 0.05) and fat mass (−31.6%, p < 0.05) as well as in all assessed physical performance variables (−9.2 - −20.2%, p < 0.05), testosterone (−73.7%, p < 0.001) and IGF-1 concentrations (−43.6%, p < 0.001). At the same time, the sex hormone-binding globulin, creatine kinase, and C-reactive protein values increased significantly (46.3–1952.7%, p < 0.05). After the 10-day recovery period, the body composition and hormonal values returned to the baseline (p < 0.05), as did some physical performance variables, such as 2 min sit-ups and the evacuation test (p < 0.05). However, explosive force production in the upper and lower bodies remained unrecovered. The 20-day winter military training caused significant physiological and mental stress, as well as a drastic decline in physical performance even for highly physically fit soldiers, and the 10-day recovery period did not establish full recovery.