Serum Growth Hormone Concentrations Research Articles

Fresh and cryopreserved semen, minerals, hormones and health characteristics in response to reciprocal combinations of vitamin D3 and 25-hydroxyvitamin D3 in the mature and prepubertal Holstein bulls' diet

The objective of this study was to evaluate the effect of supplementation of 25-hydroxyvitamin D3 (25(OH)VD3) instead of vitamin D3 on the quality and seminal plasma antioxidant indicators of fresh and cryopreserved semen, serum minerals, vitamin D3 status, hormone levels, blood biochemistry, antioxidant and immune function in different age of bulls. Thirty-two Holstein bulls (16 bulls aged 24–36 months and weighted 727 ± 99.0 kg; 16 bulls aged 12 months and weighted 332 ± 24.9 kg) randomly assigned to 1 of 4 treatments in a 2 × 2 factorial arrangement with 2 sources of vitamin D3 (vitamin D3 or 25(OH)VD3) fed at 300 IU/kg dry matter intake and two different age of bull (maturity or prepuberty) through a 60 day period. Bulls were tied in individual pens without access to sunlight. Bulls fed 25(OH)VD3 had greater semen concentration (P = 0.03), sperms motility (P = 0.02), viability (P < 0.001), membrane integrity (P < 0.001) and seminal plasma antioxidant capacity (P < 0.05) at fresh stage compared with bulls fed vitamin D3. In addition, 25(OH)VD3 increased sperms motility (P = 0.02) and membrane integrity (P = 0.04) in cryopreserved semen. Feeding 25(OH)VD3 increased serum total calcium (P = 0.03), total phosphorus (P < 0.001), 25(OH)VD3 (P < 0.001), 1,25-dihydroxyvitamin D3 (P < 0.001) compared with dietary vitamin D3. Feeding 25(OH)VD3 improved concentrations of serum estradiol (P = 0.02), testosterone (P = 0.003) and growth hormone (P < 0.001) and decreased serum cortisol (P = 0.01). Lower blood urea nitrogen (P = 0.005), creatinine (P = 0.02), aspartate aminotransferase (P = 0.005) and higher serum glucose (P = 0.03) were observed in the 25(OH)VD3. Dietary 25(OH)VD3 increased serum glutathione (P = 0.001) and immunoglobulin M (P = 0.03) and decreased malondialdehyde (P = 0.04) compared to those fed vitamin D3. The total antioxidant capacity was affected by interaction of age and vitamin D source (P < 0.001). In conclusion, replacing vitamin D3 with 25(OH)VD3 improved semen quality and benefited health of the mature and prepubertal Holstein bulls.

The Influence of Long-Term Treatment with Asenapine on Liver Cytochrome P450 Expression and Activity in the Rat. The Involvement of Different Mechanisms.

Therapy of schizophrenia requires long-term treatment with a relevant antipsychotic drug to achieve a therapeutic effect. The aim of the present study was to investigate the influence of prolonged treatment with the atypical neuroleptic asenapine on the expression and activity of rat cytochrome P450 (CYP) in the liver. The experiment was carried out on male Wistar rats. Asenapine (0.3 mg/kg s.c.) was administered for two weeks. The levels of CYP mRNA protein and activity were determined in the liver and hormone concentrations were measured in the pituitary gland and blood serum. Asenapine significantly decreased the activity of CYP1A (caffeine 8-hydroxylation and 3-N-demethylation), CYP2B, CYP2C11 and CYP3A (testosterone hydroxylation at positions 16β; 2α and 16α; 2β and 6β, respectively). The neuroleptic did not affect the activity of CYP2A (testosterone 7α-hydroxylation), CYP2C6 (warfarin 7-hydroxylation) and CYP2E1 (chlorzoxazone 6-hydroxylation). The mRNA and protein levels of CYP1A2, CYP2B1, CYP2C11 and CYP3A1 were decreased, while those of CYP2B2 and CYP3A2 were not changed. Simultaneously, pituitary level of growth hormone-releasing hormone and serum concentrations of growth hormone and corticosterone were reduced, while that of triiodothyronine was enhanced. In conclusion, chronic treatment with asenapine down-regulates liver cytochrome P450 enzymes, which involves neuroendocrine mechanisms. Thus, chronic asenapine treatment may slow the metabolism of CYP1A, CYP2B, CYP2C11 and CYP3A substrates (steroids and drugs). Since asenapine is metabolized by CYP1A and CYP3A, the neuroleptic may inhibit its own metabolism, therefore, the plasma concentration of asenapine in patients after prolonged treatment may be higher than expected based on a single dose.

Genetic Characterization of Short Stature Patients With Overlapping Features of Growth Hormone Insensitivity Syndromes.

ContextGrowth hormone insensitivity (GHI) in children is characterized by short stature, functional insulin-like growth factor (IGF)-I deficiency, and normal or elevated serum growth hormone (GH) concentrations. The clinical and genetic etiology of GHI is expanding.ObjectiveWe undertook genetic characterization of short stature patients referred with suspected GHI and features which overlapped with known GH–IGF-I axis defects.MethodsBetween 2008 and 2020, our center received 149 GHI referrals for genetic testing. Genetic analysis utilized a combination of candidate gene sequencing, whole exome sequencing, array comparative genomic hybridization, and a targeted whole genome short stature gene panel.ResultsGenetic diagnoses were identified in 80/149 subjects (54%) with 45/80 (56%) having known GH–IGF-I axis defects (GHR n = 40, IGFALS n = 4, IGFIR n = 1). The remaining 35/80 (44%) had diagnoses of 3M syndrome (n = 10) (OBSL1 n = 7, CUL7 n = 2, and CCDC8 n = 1), Noonan syndrome (n = 4) (PTPN11 n = 2, SOS1 n = 1, and SOS2 n = 1), Silver–Russell syndrome (n = 2) (loss of methylation on chromosome 11p15 and uniparental disomy for chromosome 7), Class 3-5 copy number variations (n = 10), and disorders not previously associated with GHI (n = 9) (Barth syndrome, autoimmune lymphoproliferative syndrome, microcephalic osteodysplastic primordial dwarfism type II, achondroplasia, glycogen storage disease type IXb, lysinuric protein intolerance, multiminicore disease, macrocephaly, alopecia, cutis laxa, and scoliosis syndrome, and Bloom syndrome).ConclusionWe report the wide range of diagnoses in 149 patients referred with suspected GHI, which emphasizes the need to recognize GHI as a spectrum of clinical entities in undiagnosed short stature patients. Detailed clinical and genetic assessment may identify a diagnosis and inform clinical management.

Leptin Modulates the Response of Brown Adipose Tissue to Negative Energy Balance: Implication of the GH/IGF-I Axis.

The growth hormone (GH)/insulin-like growth factor I (IGF-I) axis is involved in metabolic control. Malnutrition reduces IGF-I and modifies the thermogenic capacity of brown adipose tissue (BAT). Leptin has effects on the GH/IGF-I axis and the function of BAT, but its interaction with IGF-I and the mechanisms involved in the regulation of thermogenesis remains unknown. We studied the GH/IGF-I axis and activation of IGF-I-related signaling and metabolism related to BAT thermogenesis in chronic central leptin infused (L), pair-fed (PF), and control rats. Hypothalamic somatostatin mRNA levels were increased in PF and decreased in L, while pituitary GH mRNA was reduced in PF. Serum GH and IGF-I concentrations were decreased only in PF. In BAT, the association between suppressor of cytokine signaling 3 and the IGF-I receptor was reduced, and phosphorylation of the IGF-I receptor increased in the L group. Phosphorylation of Akt and cyclic AMP response element binding protein and glucose transporter 4 mRNA levels were increased in L and mRNA levels of uncoupling protein-1 (UCP-1) and enzymes involved in lipid anabolism reduced in PF. These results suggest that modifications in UCP-1 in BAT and changes in the GH/IGF-I axis induced by negative energy balance are dependent upon leptin levels.

The Protective Role of Alpha-Ketoglutaric Acid on the Growth and Bone Development of Experimentally Induced Perinatal Growth-Retarded Piglets.

Simple SummaryPerinatal growth restriction is a significant health issue that predisposes to a reduced rate of postnatal weight gain and the development of numerous diseases later in life. In livestock production, growth restricted animals require more time to reach slaughter weight. In this study, we examined the effects of long-term administration of alpha-ketoglutaric acid (AKG) on the growth and development of experimentally-induced, perinatal growth-retarded piglets.The effect of alpha-ketoglutaric acid (AKG) supplementation to experimentally-induced, perinatal growth-retarded piglets was examined. Sows were treated with a synthetic glucocorticoid (Gc) during the last 25 days of pregnancy, and after the birth, piglets were randomly divided into three groups depending on the treatment. The Gc/Gc + AKG and Gc/AKG groups born by Gc-treated sows after the birth were treated with Gc or Gc + AKG for 35 days. Significantly lower serum growth hormone, IGF-I, osteocalcin, leptin, and cortisol concentrations were observed in the Gc/Gc + AKG group, while the bone alkaline phosphatase activity was significantly higher. Serum insulin concentration was higher in the control group. Serum alanine, lysine, histidine, and tryptophan concentrations were higher in the Gc/Gc + AKG and Gc/AKG groups. The perinatal action of Gc significantly affects histomorphometry of articular cartilage and trabecular bone and bone mechanics. The results clearly showed that dietary AKG had positive effects with regards to the profile of free amino acids. Taking into account the function of AKG as an energy donor and stimulator of collagen synthesis, it can be concluded that the anabolic role of AKG may be the main mechanism responsible for its protective effect against the GC-induced perinatal intensified catabolic state.

The Prevalence of Cancer and Its Relation to Disease Activity in Patients With Acromegaly: Two Centers' Experience

ObjectiveAcromegaly is characterized by increased serum concentrations of growth hormone (GH) and insulin-like growth factor 1 (IGF-1). Although animal studies have demonstrated a relationship between these hormones and cancer risk, the results of human studies evaluating cancer prevalence in acromegaly are inconsistent. We aimed to investigate the prevalence of malignant neoplasms in patients with acromegaly. MethodsCancer risk was evaluated in a cohort of 280 patients (male/female: 120/160; mean age: 50.93 ± 12.07 years) with acromegaly. Patients were categorized into 2 groups according to the presence or absence of cancer. Standard incidence ratios were calculated as compared to the general population. ResultsFrom 280 patients, cancer was diagnosed in 19 (6.8%) patients; 9 (47%) of them had thyroid cancer, which was the most common cancer type. Standard incidence ratios of all cancers were 0.8 (95% CI, 0.5-1.1) and 1.0 (95% CI, 0.8-1.3) in men and women, respectively. Compared to patients without cancer, the current age was higher in patients with cancer (59 [49-65] to 51 [42-59], P = .027). In contrast, the age at diagnosis was similar in both groups. Not only was the time to diagnosis and disease duration similar in both groups but also the basal and current GH and IGF-1 levels. The prevalence of active disease was also similar between the groups (32% to 23%, P = .394). ConclusionOur findings were not consistent with the studies suggesting that patients with acromegaly encounter an increased cancer risk. Furthermore, there were similar basal and current GH and IGF-1 levels in patients with acromegaly, both with and without cancer.

Effects of Bushen Zhuanggu Granules on expressions of serum GH with IGF-1 and its receptors in bone tissue of ovariectomized rats

Objective: To investigate the effects of Bushen Zhuanggu granule on the expressions of serum growth hormone (GH) and insulin-like growth factor-1(IGF-1) and their receptors in bone tissues of ovariectomized rats. Methods: Forty-eight SD female rats (weight 273±21.3 g) were divided into 4 four groups: the dosage of Bushen Zhuanggu granule group (BSZG) was 2.5 g/(kg·d),the do -sage of estradiol group(E2) was 0.071mg/(kg·d),sham group (SHAM) and ovariectomized model group (OVX group) were given the same amount of saline by oral administration.Each group included 12 rats,the treatments were conducted once a day. After 3 and 6 months of treatment,bone mineral density (B -MD) was measured by bone density instrument;the serum levels of GH and IGF-1 were detected by EL-ISA;the expressions of GHR and IGF-1R of bone tissue were detected by qPCR;the optical density(OD)value and positive cell count of pituitary GH immunohistochemical tablets were analyzed by Image J software,respectively. Results: ①After 3 months intervention,compared with the SHAM, the BMD of the spine in E2 group was increased(P＜0.05),and the BMD of both parts in BSZG group were increased(P＜0.05).After two stage intervention,BMD of both part in the two drug groups was higher than that in the OVX group(P＜0.05).②After two-stage intervention,the expression levels of serum GH and IGF-1,GHR and IGF-1R in BSZG group were higher than those in OVX group (P＜0.05).The levels of serum GH and it's receptors in the E2 group were increased (P＜0.05), but the serum IGF-1 level remained unchanged (P＞0.05) or even was decreased (P＜0.05).③After two stage in -tervention,the OD values and the positive cells count in the two drug intervention groups were increased (P＞0.05).④Pearson correlation analysis showed that serum GH,IGF-1 concentration and it's receptors in bone tissue were positively related with BMD. Serum GH concentration was positively correlated with OD values and number of positive cells. Conclusion: Bushen Zhuanggu granule can be used to improve the expressions of GH,IGF-1 in serum and its receptors in bone tissues of ovariectomized osteoporosis rats to prevent further loss of bone mass and increase bone mineral density.

Growth hormone and periarticular new bone formation--a causal relationship? A preliminary communication

In an attempt to examine the relationship between growth hormone (GH) and periarticular new bone formation (PNBF), we studied eight patients with brain lesions of different origins who were in a prolonged comatose state for 164 to 1320 days. Five of them developed PNBF. The latter reacted to both the specific L-Dopa test and to the non-specific TRH test with an increase in GH serum concentration. Those patients who did not develop PNBF, failed to react significantly to either tests. The difference in GH values between the two groups is statistically significant at the 95% level of confidence. We hypothesize that there may be a causal relationship between high concentrations of GH in serum and PNBF.

Insulin synthesized in the paraventricular nucleus of the hypothalamus regulates pituitary growth hormone production.

Evidence has mounted that insulin can be synthesized in various brain regions, including the hypothalamus. However, the distribution and functions of insulin-expressing cells in the hypothalamus remain elusive. Herein, we show that in the mouse hypothalamus, the perikarya of insulin-positive neurons are located in the paraventricular nucleus (PVN) and their axons project to the median eminence; these findings define parvocellular neurosecretory PVN insulin neurons. Contrary to corticotropin-releasing hormone expression, insulin expression in the PVN was inhibited by restraint stress (RS) in both adult and young mice. Acute RS–induced inhibition of PVN insulin expression in adult mice decreased both pituitary growth hormone (Gh) mRNA level and serum GH concentration, which were attenuated by overexpression of PVN insulin. Notably, PVN insulin knockdown or chronic RS in young mice hindered normal growth via the downregulation of GH gene expression and secretion, whereas PVN insulin overexpression in young mice prevented chronic RS–induced growth retardation by elevating GH production. Our results suggest that in both normal and stressful conditions, insulin synthesized in the parvocellular PVN neurons plays an important role in the regulation of pituitary GH production and body length, unveiling a physiological function of brain-derived insulin.

Endocrine Aspects of Kidney Disease

Kidneys play the major role in the synthesis and degradation of several hormones. Different coexisting conditions such as inflammation, malnutrition and metabolic acidosis and applied treatment may also cause endocrine abnormalities in chronic kidney disease (CKD) patients. A tendency towards decreased thyroxin and triiodothyronine with normal serum concentrations of reversed triiodothyronine (as opposed to other chronic non-thyroid, non-kidney diseases) and thyroid stimulating hormone are observed. As far as the somatotopic axis is concerned, in CKD normal serum concentration of growth hormone and its effector – the insulin-like growth factor are observed. Nevertheless, due to the phenomenon of GH/IGF-1 “resistance” CKD patients usually present a phenotype resembling GH deficiency. Serum prolactin concentrations are often elevated in CKD women and men. This leads to the dysregulation of the pituitary-gonadal axis causing hypogonadism and it’s clinical consequences regardless of patient’s gender. The alterations in hormones of gonadal origin caused by uremia, together with hyperprolactinemia lead to the development of sexual dysfunction and infertility in men and women. The alterations of thyroid, pituitary gland and gonads associated with CKD are discussed in this chapter. This review contains 4 tables, and 64 references. Keywords: chronic kidney disease, hypothyroidism, hyperthyroidism, growth hormone, recombinant human GH, insulin-like growth factors, hemodialysis

Effects of Dietary Protein Levels on Growth Performance, Carcass Traits, Serum Metabolites, and Meat Composition of Tibetan Sheep during the Cold Season on the Qinghai-Tibetan Plateau.

Simple SummaryThe Tibetan sheep (Ovis aries) is an ovine breed well adapted to the harsh plateau environment. For a long period of time, Tibetan sheep farming has been an important pillar industry for native herders on the Qinghai-Tibetan Plateau. With the increasing demand for sheep meat and products, nutrition research has gained increasing importance. In this study, the effects of three different dietary protein levels (10.1%, 12.1%, and 14.1%) on growth performance, carcass traits, serum metabolites, and meat composition were investigated in Tibetan sheep during the cold season. The results showed that the diets containing 12.1% and 14.1% protein were better than a diet containing 10.1% protein for enhancing the growth performance, carcass performance, and meat products of the Tibetan sheep.Dietary protein is a critical nutrient that directly influences the health and production of livestock. Recent studies showed that protein supplements could enhance the growth performance of Tibetan sheep. However, there is a lack of information regarding the influence of dietary protein levels on carcass traits and meat composition. This study investigated the effects of dietary protein levels on growth performance, carcass traits, serum metabolites, and meat composition in Tibetan sheep during the cold season on the Qinghai-Tibetan Plateau. A total of eighteen 1-year-old, healthy, castrated Tibetan sheep with similar initial body weights (31.7 ± 0.72 kg) were randomly divided into three treatment groups with different dietary protein level (low protein (LP, 10.1%); medium protein (MP, 12.1%); high protein (HP, 14.1%)) diets. The results indicated that the Tibetan sheep fed with the MP and HP diets had greater final body weights (BWs), average daily gains (ADGs), and average daily feed intakes (ADFIs) (p < 0.05). The MP and HP diets also improved the hot carcass weight, net meat (including the fat) weight, and bone weight of the sheep significantly (p < 0.05). Besides, the dietary protein levels could significantly affect the serum concentrations of growth hormone (p < 0.05). The diameter of muscle fibers in the MP group was significantly greater than that in the LP group (p < 0.05), while the density of muscle fibers showed the opposite trend. The dietary protein levels only significantly (p < 0.05) influenced the ether extract content and profile content of the longissimus dorsi muscle but had no effect on other parameters of meat composition. In summary, our results indicate that dietary protein levels affect growth performance, carcass traits, and meat composition and that diets containing 12.1% and 14.1% protein are recommended to obtain better production performance and meat products in Tibetan sheep, rather than a diet containing 10.1% protein, during the cold season on the Qinghai-Tibetan Plateau.

Nutritional effects pre-weaning on growth performance, carcass traits and meat quality of pigs

The objective of the present study was to investigate the effect of nutritional restriction during the suckling period on growth performance, carcass traits and meat quality of fattening pigs. A one-way experimental design was used. In total, 24 male pigs of normal birthweight (1.54 ± 0.05 kg) were randomly allocated at 7 days of age to three groups: control, fed ad libitum; 30% nutritional restriction (Re30%); and 60% nutritional restriction (Re60%). The Re30% and Re60% groups showed decreased average daily gain, average daily feed intake and feed conversion ratio from Day 7 to Day 28. After Day 28, differences in these parameters were observed only in the Re60% group relative to the control. With regard to hormone levels, the Re60% group showed decreased serum concentration of insulin-like growth factor-1 at Day 28 and increased serum concentration of growth hormone at Day 147. Furthermore, the Re60% group had decreased carcass weight, ham weight and dressing percentage, and increased carcass lean percentage relative to the control, as well as lower cross-sectional area and myofibre diameter of muscle. The Re60% group had lower levels of myosin heavy chain (MyHC) IIx and MyHC IIb mRNA and a higher percentage of MyHC I and MyHC IIa mRNA in longissimus dorsi muscle than the Re30% group. In conclusion, nutritional restriction during the suckling period decreased weaning weight, with post-weaning growth performance, carcass traits and myofibre type affected in the Re60% group rather than Re30% group.

Comparison Between Two Volume-Matched Squat Exercises With and Without Momentary Failure for Changes in Hormones, Maximal Voluntary Isometric Contraction Strength, and Perceived Muscle Soreness.

Shibata, K, Takizawa, K, Tomabechi, N, Nosaka, K, and Mizuno, M. Comparison between two volume-matched squat exercises with and without momentary failure for changes in hormones, maximal voluntary isometric contraction strength and perceived muscle soreness. J Strength Cond Res 35(11): 3063-3068, 2021-The present study compared 2 squat exercises with and without momentary failure (MF) for changes in blood hormones, maximal voluntary isometric contraction (MVC) strength, and perceived muscle soreness (SOR). Ten physically active male students performed squat exercises at 75% of their 1 repetition maximum in 2 conditions. First, they performed each set to MF for 3 sets, and 2 weeks later, performed the same number of repetitions in 6 sets without MF (NMF). The rate of perceived exertion was assessed at 30 minutes after exercise. Blood lactate, serum concentrations of growth hormone (GH), testosterone, insulin-like growth factor 1 (IGF-1) and cortisol, MVC strength, and SOR were measured before and after each exercise. Rate of perceived exertion was higher (p < 0.01) in MF (8.3 ± 1.2) than in NMF (4.1 ± 1.4). Blood lactate was greater (p < 0.01) at 5 minutes after MF (7.2 ± 0.7 mM·L-1) than NMF (3.6 ± 0.7 mM·L-1). At 30 minutes after exercise, GH (MF: 12.3 ± 8.3 ng·ml-1, NMF: 4.4 ± 5.2 ng·ml-1) and cortisol (MF: 19.0 ± 4.3 μg·dl-1, NMF: 14.2 ± 4.6 μg·dl-1) were greater (p < 0.01) for MF than NMF, but no significant differences were observed between conditions for testosterone and IGF-1. Maximal voluntary isometric contraction strength decrease (6.1 ± 8.8%) at 24 hours after exercise was evident only for MF, but SOR at 24 hours after exercise was similar between MF (4.8 ± 3.3 cm) and NMF (2.5 ± 2.4 cm) conditions. These results suggest that mechanical and metabolic stimulus to the muscles were greater for MF than NMF condition.

GLUTAMINE SUPPLEMENTATION: EFFECTS ON GROWTH HORMONE AND TIME-TRIAL PERFORMANCE AFTER PROLONGED EXERCISE

Dietary glutamine supplementation has been proposed as a potential aid to athletic performance. The purpose of the investigation was to determine if glutamine supplementation might improve cycling performance, perhaps by stimulating growth hormone release, in athletes consuming a high-carbohydrate diet. Six trained young adult men participated in two four-day supplementation trials. In both trials, the subjects underwent an identical carbohydrate-loading regimen of controlled diet (75% carbohydrate) and exercise. The only difference in the trials was whether the subjects ingested dietary supplements of glutamine or glucose placebo. During the first three days of each trial, the diets were supplemented with either glutamine or glucose placebo at a dosage of 150 mg/kg body weight (~10.4 g/d). On the fourth day, the supplements were dissolved in a sports drink (4 g/L). The sports drink initially contained a 6% solution of carbohydrate. On the fourth day the subjects ingested 7 ml/kg of the supplemented sports drink 2 h before exercise, 5 ml/kg 1 h before exercise, and 3 ml/kg after 15, 30, 45, 60, and 90 min of exercise. The total amount of glutamine supplement or placebo consumed on the fourth day was 108 mg/kg or about 7.4 g, of which 3.3 g were consumed before and 4.1 g during exercise. On the fourth day, subjects completed 90 min of cycle ergometry, divided into six 15-min periods, each of which included in sequence 12 min @75% VO2max, 1 min @ 120% VO2max, and 2 min @ 50% VO2max. The 90 min exercise session was immediately followed by 15 min of rest and then a final 20-km time trial at ~85% VO2max. Plasma concentrations of glycerol and free fatty acids and serum growth hormone concentrations were measured before and during exercise, and time-trial performance was recorded. Times (± SEM) to complete the 20-km performance rides were 31.03 ± 0.58 min for the placebo trial and 30.93 ± 0.60 min for the glutamine trial and were not significantly different (P&gt;0.05). There were also no significant effects on serum growth hormone or on plasma glycerol or free fatty acids attributable to glutamine supplementation at any sampling time. In summary, we found no evidence that glutamine supplementation in moderate dosages has any effect on circulating growth hormone, glycerol, or free fatty acids or on time-trial performance in athletes who consume a high-carbohydrate diet

Resistance exercise-induced hormonal response promotes satellite cell proliferation in untrained men but not in women

The purpose of this work was to determine the effect of resistance exercise (RE)-induced hormonal changes on the satellite cell (SC) myogenic state in response to muscle damage. Untrained men (n = 10, 22 ± 3 yr) and women (n = 9, 21 ± 4 yr) completed 2 sessions of 80 unilateral maximal eccentric knee extensions followed by either an upper body RE protocol (EX) or a 20-min rest (CON). Muscle samples were collected and analyzed for protein content of Pax7, MyoD, myogenin, cyclin D1, and p21 before (PRE), 12 h, and 24 h after the session was completed. Serum testosterone, growth hormone, cortisol, and myoglobin concentrations were analyzed at PRE, post-damage, immediately after (IP), and 15, 30, and 60 min after the session was completed. Testosterone was significantly (P < 0.05) higher immediately after the session in EX vs. CON for men. A significant time × sex × condition interaction was found for MyoD with an increase in EX (men) and CON (women) at 12 h. A significant time × condition interaction was found for Pax7, with a decrease in EX and increase in CON at 24 h. A significant time effect was found for myogenin, p21, and cyclin D1. Myogenin and p21 were increased at 12 and 24 h, and cyclin D1 was increased at 12 h. These results suggest that the acute RE-induced hormonal response can be important for men to promote SC proliferation after muscle damage but had no effect in women. Markers of SC differentiation appeared unaffected by the hormonal response but increased in response to muscle damage.

Resistance Exercise-Induced Hormonal Response Promotes Satellite Cell Proliferation in Untrained Men

Evidence suggests that resistance exercise (RE)-induced transient release of anabolic hormones can be beneficial for muscle adaptation (e.g. muscle size, strength); however, no prior research appears to have investigated the effect of the RE-induced hormonal response on satellite cell (SC) proliferation and differentiation, an important step in any such muscle adaptations. PURPOSE: To determine the effect of transient resistance exercise (RE)-induced hormonal changes on satellite cell myogenic state following eccentric exercise. METHODS: Untrained men (n=10, 22±3y) and women (n=9, 21±4y) completed 2 sessions of 80 unilateral maximal eccentric knee extensions followed by either an upper body RE protocol (EXE) or a 20-min rest (CON). Muscle samples were collected and analyzed for protein content of Pax7, MyoD, myogenin, cyclin D1, and p21 before exercise (PRE), and 12 hours (+12h) and 24 hours after the session (+24h). Serum testosterone, growth hormone, cortisol, and myoglobin concentrations were measured at PRE, immediately after eccentric knee extension (IMD), immediately after (IP), 15, 30, and 60 min after the session. RESULTS: Testosterone was significantly (p<0.05) higher immediately after the session in EXE (6.34 ± 0.48 ng·ml-1) than CON (4.87 ± 0.26 ng·ml-1) for men. A significant time x gender x condition interaction was found for MyoD with 20.1 ± 10.8-fold increase for EXE in men and 21.9 ± 7.6-fold increase for CON in women at +12h compared to PRE. A significant time x condition interaction was found for Pax7 with 0.8 ± 0.1-fold decrease for EXE and 1.6 ± 0.3-fold increase for CON at +24h compared to PRE. A significant time effect was found for myogenin, p21, and cyclin D1. Myogenin (+12h: 5.9 ± 1.5-fold; +24h: 5.0 ± 1.1-fold) and p21 (+12h: 25.4 ± 4.5-fold; +24h: 12.4 ± 1.9-fold) were increased at +12h and +24h and Cyclin D1 was 6.6 ± 1.9-fold increased at +12h compared to PRE. CONCLUSION: These results suggest that the RE-induced hormonal response can be important to promote SC proliferation for men but not women. In addition, markers of SC differentiation appeared to be unaffected by the hormonal response but were increased in response to the knee eccentric exercise protocol. Supported in part by a grant from the National Strength and Conditioning Association Foundation

Effects of isomaltooligosaccharide and Bacillus supplementation on sow performance, serum metabolites, and serum and placental oxidative status

This study investigated the effects of isomaltooligosaccharide (IMO) and Bacillus supplementation on sow performance, serum metabolites, and serum and placental oxidative status. Multiparous gestating sows (n = 130) with similar body conditions were randomly allocated to five groups (n = 26) receiving a basal diet (CON group) or a basal diet supplemented with 0.5% IMO (IMO group); 0.5% IMO and 0.02% Bacillus subtilis (IMO + S group); 0.5% IMO and 0.02% Bacillus licheniformis (IMO + L group); or 0.5% IMO, 0.02% Bacillus subtilis, and 0.02% Bacillus licheniformis (IMO + S+L group). There were no significant differences in the litter sizes among all dietary groups. The average piglet birth weight was improved in all treatment groups, and the placental efficiency was greater in the IMO + S and IMO + S+L groups than in the CON group (P < 0.05). The IMO + S+L group had increased the low-density lipoprotein cholesterol and reduced the total cholesterol in umbilical venous serum (P < 0.05). Additionally, the malondialdehyde concentrations were greater in umbilical venous serum of piglets in all treatment groups relative to that in the CON piglets (P < 0.05). The placental total antioxidant capacity was increased in the IMO+L and IMO+S+L groups (P < 0.05). Furthermore, the growth hormone concentration in umbilical venous serum was greater (P < 0.05) in all treatment groups. Overall, IMO and Bacillus supplementation during late gestation resulted in a changed metabolism of sows, improved the placental antioxidant capacity, and increased the growth hormone concentrations in umbilical venous serum, which ultimately improved the piglet birth weight and placental efficiency.

Reduced dietary nitrogen with a high Lys:CP ratio restricted dietary N excretion without negatively affecting weaned piglets.

We hypothesized that balancing the content of exogenous amino acids, especially lysine, to reduce protein content in swine diets could reduce nitrogen (N) pollution associated with animal husbandry. Two experiments (45 d each experiment) were performed on weaned piglets (Duroc × Landrace × Yorkshire, 28 d of age) to test this and to determine the optimal lysine to crude protein (Lys:CP) ratio in diet. In Exp. 1, 12 piglets (6 replicates [n = 6]) were fed diets containing different levels of CP (17% and 20%) but the same level of Lys. Increased CP content resulted in significant increases (P < 0.05) of average daily gain (ADG), average daily feed intake (ADFI), and body weight (BW), but did not affect the feed to gain ratio. In Exp. 2, 24 piglets (8 replicates [n = 8]) were fed 1 of 3 diets as follows: 1) 20% CP with a regular Lys:CP ratio (6.23%, control); 2) 17% CP with a reduced Lys:CP ratio (6.14%, LL); or 3) 17% CP with a standard Lys:CP ratio (7.32%, SL). The ADG, final BW, serum concentrations of growth hormone and insulin-like growth factor-1, villus height in the jejunum, and villus height to crypt depth ratio were the lowest in piglets fed LL diet, whereas blood urea N concentration was the lowest and the value of lipase activity was the highest in the piglets fed SL diet. The SL diet did not affect growth performance, intestinal morphology, or serum hormone concentrations, indicating that reduced dietary N with a high Lys:CP ratio can efficiently reduce dietary N excretion without negatively affecting weaned piglets.

The response of gene expression associated with intramuscular fat deposition in the longissimus dorsi muscle of Simmental×Yellow breed cattle to different energy levels of diets.

This study was designed to estimate dietary energy level on intramuscular fat (IMF) deposition in Simmental×Yellow breed cattle. Results showed that ultimate weight and average daily gain in high and medium energy groups were significantly higher than low-energy group, yet feed conversion ratio was significantly lower. IMF content was significantly increased by dietary energy increasing, whereas longissimus muscle shear force significantly decreased. Serum-free fatty acids, triglycerides and glucose significantly increased by dietary energy increasing, whereas growth hormone (GH) significantly decreased. Enzyme activities of lipoprotein lipase (LPL), fatty acid synthase (FAS), and acetyl-CoA carboxylase (ACC) significantly increased by dietary energy increasing, whereas hormone-sensitive lipase (HSL) and carnitine palmitoyltransferase-1 (CPT-1) significantly diminished. Peroxisome proliferator-activated receptor γ, sterol regulatory element-binding protein 1, stearoyl-CoA desaturase, adipocyte-fatty acid-binding proteins, ACC, LPL, and FAS gene or protein expression significantly increased by dietary energy increasing, whereas HSL, CPT-1, and GH gene or protein expression significantly decreased. These results indicated that high dietary energy promoting IMF deposition is mainly by downregulating pituitary GH gene expression, decreasing serum GH concentration, increasing lipogenic genes levels of mRNA, enzyme activities and protein expression, and decreasing lipolytic genes levels of mRNA, enzyme activities, and protein expression.

Dietary Energy Levels Affect Growth Performance through Growth Hormone and Insulin-Like Growth Factor 1 in Yak (Bos grunniens).

Simple SummaryYak is always in a malnutrition condition under pure grazing in the cold season. Many studies have suggested that provision of supplementary feed to yak cannot only be an effective approach to avoid weight loss, but also improve productivity. Growth hormone (GH) and insulin-like growth factor 1 (IGF-1) could improve yak productivity. In current work, we evaluated the effects of different energy feedstuffs on the serum concentration of GH, IGF-1, and relative hepatic expression of their associated binding proteins and receptors, as well as growth performance of yak. The results indicated that average daily gain (ADG), body weight (BW), feed conversion ratio, serum IGF-1 concentration, and relative expression of IGF-1 and IGFBP-3 were increased with an increase in dietary energy level, while serum GH concentration and hepatic growth hormone (GHR) expression were decreased. Serum IGF-1 concentration, relative hepatic expression of IGF-1, and insulin-like growth factor binding protein 3 (IGFBP-3) showed positive correlation with ADG, but serum GH concentration and GHR expression were negatively correlated with ADG. Yak offered with medium energy diet (NEg: 6.2 MJ/kg) displayed better growth by gaining 0.883 kg/d and showing a superior feed conversion ratio during experiment.The objective of this study was to investigate the effects of different dietary energy levels on serum concentrations of growth hormone (GH) and insulin-like growth factor 1 (IGF-1), as well as gene expression of their associated binding proteins and receptors in yak. Fifteen adult male yaks with BW of 276.1 ± 3.5 kg were allotted in three dietary groups and were fed with low (LE), medium (ME), and high energy (HE) level diet having different NEg of 5.5 MJ/kg, 6.2 MJ/kg, 6.9 MJ/kg, respectively. The effects of these treatments on ADG, BW, ADFI, and feed conversion ratio were significant (p < 0.05) throughout the experimental period. Serum GH concentration decreased (p < 0.05) with an increase in dietary energy level on d 30 and d 60. While IGF-1 concentration was higher (p < 0.05) in ME group, as compared to LE and HE groups on d 60. The expression level of growth hormone receptor (GHR) was decreased (p < 0.001) and IGF-1 was increased with the increase in the dietary energy level. The relative expression of insulin-like growth factor binding protein 3 (IGFBP-3) was higher (p < 0.001) in ME and HE groups, except the LE group. In conclusion, our findings provide a first insight into the combined effect of GH and IGF-1 in controlling the metabolism and productivity of yak. It also showed that medium energy level diet contributed to promote growth performance of yak during the cold season.