Insulin-Like Growth Factor Binding Protein-6: Posttranslational modifications and sorting in polarized MDCK cells

The six high-affinity insulin-like growth factor-binding proteins (IGFBPs) comprise a conserved family of secreted molecules that modulate IGF actions by regulating their half-life and access to signaling receptors, and also exert biological effects that are independent of IGF binding. IGFBPs are composed of cysteine-rich amino- (N-) and carboxyl- (C-) terminal domains, along with a cysteine-poor central linker segment. IGFBP-5 is the most conserved IGFBP, and contains 18 cysteines, but only 2 of 9 putative disulfide bonds have been mapped to date. Using a mass spectrometry (MS)-based strategy combining sequential electron transfer dissociation (ETD) and collision-induced dissociation (CID) steps, in which ETD fragmentation preferentially induces cleavage of disulfide bonds, and CID provides exact disulfide linkage assignments between liberated peptides, we now have definitively mapped 5 disulfide bonds in IGFBP-5. In addition, in conjunction with ab initio molecular modeling we are able to assign the other 4 disulfide linkages to within a GCGCCXXC motif that is conserved in five IGFBPs. Because of the nature of ETD fragmentation MS experiments were performed without chemical reduction of IGFBP-5. Our results not only establish a disulfide bond map of IGFBP-5 but also define a general approach that takes advantage of the specificity of ETD and the scalability of tandem MS, and the predictive power of ab initio molecular modeling to characterize unknown disulfide linkages in proteins.

Phosphatidylinositol 4-phosphate (PI4P) regulates biosynthetic membrane traffic at multiple steps and differentially affects the surface delivery of apically and basolaterally destined proteins in polarized cells. Two phosphatidylinositol 4-kinases (PI4Ks) have been localized to the Golgi complex in mammalian cells, type III PI4Kbeta (PI4KIIIbeta) and type II PI4Kalpha (PI4KIIalpha). Here we report that PI4KIIIbeta and PI4KIIalpha localize to discrete subcompartments of the Golgi complex in Madin-Darby canine kidney (MDCK) cells. PI4KIIIbeta was enriched in early Golgi compartments, whereas PI4KIIalpha colocalized with markers of the trans-Golgi network (TGN). To understand the temporal and spatial control of PI4P generation across the Golgi complex, we quantitated the steady state distribution of a fluorescent PI4P-binding domain relative to cis/medial Golgi and TGN markers in transiently transfected MDCK cells. The density of the signal from this PI4P reporter was roughly 2-fold greater in the early Golgi compartments compared with that of the TGN. Furthermore, this ratio could be modulated in vivo by overexpression of catalytically inactive PI4KIIIbeta and PI4KIIalpha or in vitro by the PI4KIIIbeta inhibitor wortmannin. Our data suggest that both PI4KIIIbeta and PI4KIIalpha contribute to the compartmental regulation of PI4P synthesis within the Golgi complex. We discuss our results with respect to the kinetic effects of modulating PI4K activity on polarized biosynthetic traffic in MDCK cells.

Based on recent data showing that overexpression of the Na,K-ATPase beta(1) subunit increased cell-cell adhesion of nonpolarized cells, we hypothesized that the beta(1) subunit can also be involved in the formation of cell-cell contacts in highly polarized epithelial cells. In support of this hypothesis, in Madin-Darby canine kidney (MDCK) cells, the Na,K-ATPase alpha(1) and beta(1) subunits were detected as precisely co-localized with adherens junctions in all stages of the monolayer formation starting from the initiation of cell-cell contact. The Na,K-ATPase and adherens junction protein, beta-catenin, stayed partially co-localized even after their internalization upon disruption of intercellular contacts by Ca(2+) depletion of the medium. The Na,K-ATPase subunits remained co-localized with the adherens junctions after detergent treatment of the cells. In contrast, the heterodimer formed by expressed unglycosylated Na,K-ATPase beta(1) subunit and the endogenous alpha(1) subunit was easily dissociated from the adherens junctions and cytoskeleton by the detergent extraction. The MDCK cell line in which half of the endogenous beta(1) subunits in the lateral membrane were substituted by unglycosylated beta(1) subunits displayed a decreased ability to form cell-to-cell contacts. Incubation of surface-attached MDCK cells with an antibody against the extracellular domain of the Na,K-ATPase beta(1) subunit specifically inhibited cell-cell contact formation. We conclude that the Na,K-ATPase beta(1) subunit is involved in the process of intercellular adhesion and is necessary for association of the heterodimeric Na,K-ATPase with the adherens junctions. Further, normal glycosylation of the Na,K-ATPase beta(1) subunit is essential for the stable association of the pump with the adherens junctions and plays an important role in cell-cell contact formation.

Background Researches have showed that the extraocular muscle injection of insulin-like growth factor(IGF) results in the thickness of extraocular muscle and enhancement of contractility,and lack of IGF probably is associated with pathogenesis of strabismus.If extraocular muscle injection of insulin-like growth factor binding protein 4(IGFBP-4),an inhibitor of IGF,can further ensure the effect of IGF is still under-investigation.Objective The aim of this study was to evaluate the effects of IGFBP-4 on the developing extraocular muscle.Methods IGFBP-4 of 2 μl(1 g/L)was injected into superior rectus muscles via supraorbital margin in the left eyes of 24 postnatal l-day-old chickens once every other day for five times,and the equivalent amount of normal saline solution was used in the same way in the fellow eyes as controls.The animals were sacrificed by overdose of anesthesia 2 days after the final injection and 12 animals were randomly selected for the maximal contractility test of superior rectus muscle.The other 12 pieces of superior rectus muscle of the chickens were obtained for the hematoxylin & eosin staining to evaluate the morphology of superior rectus muscle and calculate the myofiber diameter using imaging system.Results The maximal contractility was (1.602 ± 0.080) mN and(1.815±0.O10)mN in the IGFBP-4 injection group and normal saline solution group respectivily,showing a significant difference between the two groups(t =13.65,P＜0.01).The maximal contraction force in cross-sectional area was (95.500 ± 7.420) mN/cm2 in the IGFBP-4 injection group and it was significantly lower than that of the normal saline solution group(101.510±5.220)mN/cm2(t =28.81,P＜0.01).Histological examination showed that thin myofibers were obvious more in the IGFBP-4 injection group than those with saline injection.The mean diameter was (8.7 ± 0.5) μm in the IGFBP-4 injected group,and that of the normal saline group was(9.1 ±0.4) μm,there was no significant difference between them (t =0.75,P =0.46).However,significant differences were found in the number of different diameters of myofibers between the two groups(all at P＜0.05).Conclusions IGF is one of the key nutrition factors in the development of extraocular musele.The extraocular muscle injection of IGFBP-4 may cause the dysfunction and morphologic abnormality of extraocular muscle. Key words: Extraocular muscle; Insulin-like growth factor; Insulin-like growth factor binding protein 4; Contractility

BackgroundPrevious studies have reported inconsistent results regarding the implications of deranged insulin-like growth factor 1 (IGF-1)/insulin-like growth factor-binding protein 1 (IGFBP-1) axis in patients with heart failure (HF). This study evaluates the roles of IGF1/IGFBP-1 axis in patients with HF with reduced ejection fraction (HFrEF), mid-range ejection fraction (HFmrEF), or preserved ejection fraction (HFpEF).MethodsConsecutive patients with HFrEF, HFmrEF, and HFpEF who underwent comprehensive cardiac assessment were included. The primary endpoint was the composite endpoint of all-cause death and HF rehospitalization at one year.ResultsA total of 151 patients with HF (HFrEF: n = 51; HFmrEF: n = 30; HFpEF: n = 70) and 50 control subjects were included. The concentrations of IGFBP-1 (p < 0.001) and IGFBP-1/IGF-1 ratio (p < 0.001) were significantly lower in patients with HF compared to controls and can readily distinguish patients with and without HF (IGFBP-1: areas under the curve (AUC): 0.725, p < 0.001; IGFBP-1/IGF-1 ratio: AUC:0.755, p < 0.001; respectively). The concentrations of IGF-1, IGFBP-1, and IGFBP-1/IGF-1 ratio were similar among HFpEF, HFmrEF, and HFrEF patients. IGFBP-1 and IGFBP-1/IGF-1 ratio positively correlated with N-terminal probrain natriuretic peptide (NT-proBNP) levels (r = 0.255, p = 0.002; r = 0.224, p = 0.007, respectively). IGF-1, IGFBP-1, and IGFBP-1/IGF-1 ratio did not predict the primary endpoint at 1 year for the whole patients with HF and HF subtypes on both univariable and multivariable Cox regression.ConclusionThe concentrations of plasma IGFBP-1 and IGFBP-1/IGF-1 ratio can distinguish patients with and without HF. In HF, IGFBP-1 and IGFBP-1/IGF-1 ratio positively correlated with NT-proBNP levels.

Purpose: Insulin-like growth factor 1 (IGF1) sampled within ten days of stroke has resulted in inconsistent findings. When compared to control participants, one study found elevated levels of IGF1 while another reported lower values. Despite these reported differences, there is evidence to suggest that IGF1 may have a neuroprotective effect and may be related to admitting stroke severity and functional independence at one month post-stroke. The possibility exists that a large sampling window and no consideration for insulin-like growth factor binding protein 3 (IGFBP3), may account for the differing results. The purpose of this study was to: 1) determine the difference in IGF1, IGFBP3, and IGF1 ratio in individuals with acute stroke and controls; and 2) determine the relationship of IGF1, IGFBP3, and IGF1 ratio to admission stroke severity and functional independence at one month post stroke. Methods: Blood was collected from 12 individuals with a diagnosis of acute stroke (4 males; 63.9 + 8.4 years) between 7:30 and 9:00 am, after an overnight fast, and within 72 hours of hospital admission. Blood was obtained from 12 age and gender matched healthy controls (4 males; 64.8 + 9.8 years) after an overnight fast during similar hours. Plasma was obtained from blood samples, aliquoted, and frozen within 1 hour of collection. IGF1 and IGFBP3 were quantified using standard procedure ELISAs (Alpco, Salem, NH). Admission NIH Stroke Scale and the modified Rankin Scale (mRS) at one month post stroke was obtained from the electronic medical record. Results: IGF1 (stroke: 113 ng/mL; control: 123 ng/mL, p = .59) and IGFBP3 (stroke: 2350 ng/mL; control: 2593 ng/mL, p = .33) were lower in the acute stroke patients, but not significantly. IGF1 ratio was not different (stroke: .06; control: 05; p = .55) in acute stroke compared to controls. There were no significant relationships between any IGF marker and stroke severity (p &gt; 0.50), nor mRS (p &gt; 0.50). Conclusion: We report that IGF1 and IGFBP3 is lower in acute stroke patients. A single time point of IGF1 and IGFBP3 during acute stroke may not demonstrate a neuroprotective relationship to stroke recovery. Future work should examine percent change in the IGF family to determine whether this may be a more valuable biomarker of stroke recovery.

Insulinlike growth factor binding proteins modulate the action of the insulinlike growth factors in various bioassays and may regulate the bioavailability of the insulinlike growth factors in vivo. Because the insulinlike growth factors may influence hepatic regeneration, we have examined the effect of partial hepatectomy on serum insulinlike growth factor binding proteins and on the abundance of insulinlike growth factor binding protein-1 messenger RNA in the liver. All rats were fasted before and after partial hepatectomy or sham operation to avoid the confounding effects of difference in food intake. Using a conventional protocol, 70% of the liver was removed, and groups of four or five rats were killed at different intervals after partial hepatectomy. Sham-operated rats served as controls. Pooled sera from each group of rats were analyzed by ligand blotting with 125I-insulinlike growth factor-I. Liver RNA from individual rats was analyzed by slot-blot and Northern-blot hybridization. A small decrease in the 39- to 42-kD insulinlike growth factor binding protein was apparent in sera from both the sham-operated and partial hepatectomized rats. In contrast, a dramatic increase (fivefold) in the 29-kD serum insulinlike growth factor binding protein (insulinlike growth factor binding protein-1) was apparent only in the partial hepatectomized rats. Hepatic insulinlike growth factor binding protein-1 messenger RNA abundance was significantly increased (1.99 +/- 0.18-fold; p less than 0.05) at 1 hr, reached a peak of 2.32 +/- 0.22-fold (p less than 0.01) at 3 hr after partial hepatectomy and returned to basal levels over the subsequent 6 to 12 hr.(ABSTRACT TRUNCATED AT 250 WORDS)

Insulin-like growth factor 1 (IGF-1) and insulin-like growth factor-binding protein 2 (IGFBP-2) are proteins that belong to the IGF axis, which is involved in glucose and lipid metabolism and may as well promote carcinogenesis. The aim of this study was to evaluate the serum concentration levels of IGF-1 and IGFBP-2 in patients with newly diagnosed pancreatic adenocarcinoma (PDAC) to verify their possible role in the diagnosis of the disease. The study included 69 patients with PDAC and 20 healthy controls. The concentrations of IGF-1 and IGFBP-2 were estimated by means of ELISA. The study protocol was approved by the Bioethics Committee at the Medical University of Lodz in Poland. PDAC patients compared with controls have a significantly lower mean serum IGF-1 level (45.83±30.03 vs. 70.66±60.57 ng/mL; P<0.0001). In contrast, in PDAC patients, the mean IGFBP-2 level was significantly higher compared with the control group (225.06±86.37 vs. 51.92±29.40 ng/mL; P<0.0001). The results show that, at the 0.01 sensitivity level, the IGF-1/IGFBP-2 ratio <0.85 points indicates PDAC presence. At this level of sensitivity, the test has a specificity of 0.097 (α=0.01; β=0.097; IGF-1/IGFBP-2≤0.85). Our results show that IGF-1 to IGFBP-2 ratio ≤0.85 may be a powerful PDAC indicator. Further studies in this area in a larger patient group are necessary to confirm our findings.

Circulating IGF-I and -II are bound to specific insulin-like growth factor (IGF)-binding proteins (IGFBPs), of which IGFBP-3 binds the majority of the IGFs. IGFBP-3 levels are regulated by GH and have been suggested to provide additional information on GH secretory capacity compared to IGF-I. However, the diagnostic value of IGFBP-3 is still controversial, perhaps because the quality of the available normative data for IGFBP-3 varies. It has recently been shown that a large number of individuals is required to establish reference ranges for IGF-I that take into account age, sex, body mass index (BMI), and pubertal stage. Therefore, we measured IGFBP-3, IGF-I, IGF-II, IGFBP-1, and IGFBP-2 levels by RIA in 907 healthy children to establish well characterized normative data on IGFBP-3 according to age, sex, and pubertal stage and to study the complex relationship between IGFs and their BPs in puberty. We found that IGFBP-3 levels increase with age in children, with maximal levels in puberty; girls experience peak values approximately 1 yr earlier than boys. Age, sex, height, BMI, and pubertal maturation were all important factors in determining the circulating levels of IGFBP-3, whereas IGF-I levels were unaffected by BMI. Comparison of IGFBP-3 with IGF-1 concentrations revealed that they did not exhibit the same developmental pattern in puberty. IGF-I levels increased to relatively higher levels than IGFBP-3, leading to an increasing molar ratio between IGF-I and IGFBP-3 in puberty, when growth velocity is high. Concomitantly, IGF-II and IGFBP-2 levels were unchanged throughout puberty, whereas IGFBP-1 levels declined with age in prepubertal children, with lowest values in puberty. There was a highly significant correlation between IGF-I and -II and IGFBP-3 on a molar basis (r = 0.84; P < 0.0001). Thus, we speculate that IGFBP-3 is pivotal for circulating IGF bioactivity and that the increase in the molar ratio between IGF-I and IGFBP-3 reflects an increase in free, biologically active IGF-I. In conclusion, we have provided normative data on a large group of healthy individuals and conclude that age, sex, height, BMI, and pubertal maturation have to be taken into account before a single IGFBP-3 value in a growth-retarded child can be evaluated properly.

Insulin-like growth factor binding proteins (IGFBPs) are key regulators of insulin-like growth factor (IGF) mediated signal transduction and thereby can profoundly influence cellular phenotypes and cell fate. Whereas IGFBPs are extracellular proteins, intracellular activities were described for several IGFBP family members, such as IGFBP-3, which can be reinternalized by endocytosis and reaches the nucleus through routes that remain to be fully established. Within the family of IGFBPs, IGFBP-6 is unique for its specific binding to IGF-II. IGFBP-6 was described to possess additional IGF-independent activities, which have in part been attributed to its translocation to the nucleus; however, cellular uptake of IGFBP-6 was not described. To further explore IGFBP-6 functions, we developed a new method for the purification of native human IGFBP-6 from cell culture supernatants, involving a four-step affinity purification procedure, which yields highly enriched IGFBP-6. Whereas protein purified in this way retained the capacity to interact with IGF-II and modulate IGF-dependent signal transduction, our data suggest that, unlike IGFBP-3, human IGFBP-6 is not readily internalized by human tumor cells. To summarize, this work describes a novel and efficient method for the purification of native human insulin-like growth factor binding protein 6 (IGFBP-6) from human cell culture supernatants, applying a four-step chromatography procedure. Intactness of purified IGFBP-6 was confirmed by IGF ligand Western blot and ability to modulate IGF-dependent signal transduction. Cellular uptake studies were performed to further characterize the purified protein, showing no short-term uptake of IGFBP-6, in contrast to IGFBP-3.Electronic supplementary materialThe online version of this article (doi:10.1007/s12079-011-0126-2) contains supplementary material, which is available to authorized users.

Objective To assess the relationship of methylation status of CpG islands in the promoter region of insulin-like growth factor binding protein 7 (IGFBP7) gene with the expression of IGFBP7 gene in human melanoma cell lines and primary melanocytes.Methods Primary melanocytes from human forcskin tissue as well as 4 human melanoma cell lines,including A375,M14,SK-MEL-1 and MV3,were used in this study.Bisulfite sequencing PCR (BSP) was applied to detect the methylation status of 54 CpG sites in the 5'-flanking promoter region of IGFBP7 gene in all of the melanoma cell lines and primary melanocytes.Results As hierarchical cluster analysis showed,IGFBP7-positive cells (including A375,M14 and SK-MEL-1 ) differed significantly from IGFBP7-negative cells (including MV3 cells and primary melanocytes) in the methylation pattern of IGFBP7 gene promoter region.Conclusion The methylation status of CpG island in the promoter region of IGFBP7 gene may be associated with its expression in melanoma cell lines. Key words: Melanoma; Insulin-like growth factor binding protein 7; DNA methylation

Insulin-like growth factor (IGF) binding protein-3 (IGFBP-3) is known to block IGF action and inhibit cell growth. IGFBP-3 is thought to act by sequestering free IGFs or, possibly, act via a novel IGF-independent mechanism. Supporting its role as a primary growth inhibitor, IGFBP-3 production has been shown to be increased by cell growth-inhibitory agents, such as transforming growth factor-beta (TGF-beta), and the tumor suppressor gene p53. In this paper, we demonstrate, for the first time, a novel function of IGFBP-3 as an apoptosis-inducing agent and show that this action is mediated through an IGF.IGF receptor-independent pathway. In the p53 negative prostate cancer cell line, PC-3, the addition of recombinant IGFBP-3 resulted in a dose-dependent induction of apoptosis. 125I-IGFBP-3 bound with high affinity to specific proteins in PC-3 cell lysates and plasma membrane preparations. These membrane-associated molecules may serve as receptors that mediate the direct effect of IGFBP-3 on apoptosis. In addition, in an IGF receptor-negative mouse fibroblast cell line, treatment with recombinant IGFBP-3 as well as transfection of the IGFBP-3 gene induced apoptosis, suggesting that neither IGFs nor IGF receptors are required for this action. Furthermore, treatment with TGF-beta1, a known apoptosis-inducing agent, resulted in the induction of IGFBP-3 expression 6-12 h before the onset of apoptosis. This effect of TGF-beta1 was prevented by co-treatment with IGFBP-3-neutralizing antibodies or IGFBP-3-specific antisense thiolated oligonucleotides. These findings suggest that IGFBP-3 induces apoptosis through a novel pathway independent of either p53 or the IGF.IGF receptor-mediated cell survival pathway and that IGFBP-3 mediates TGF-beta1 induced apoptosis in PC-3 cells.

Insulin-like growth factor 1 (IGF-1), an insulin sensitivity and vasculoprotective factor, associates negatively with the metabolic syndrome. However, IGF-1 is reduced by factors such as inflammation, oxidative stress and liver dysfunction. We investigated the relationship between bioavailable IGF-1 and the number of metabolic syndrome components and determined whether this relationship is independent of inflammation, oxidative stress and gamma glutamyl transferase (γ-GT; a marker of liver dysfunction). This study included 907 black and white participants stratified by sex (aged 43.0±11.8 years). Among them 63 participants had fasting glucose levels of ≥+7.0+mmol/l and/or used diabetes medication. Via standard methods we determined waist circumference, fasting glucose, triglycerides, high-density lipoprotein cholesterol and blood pressure. We also determined high-sensitivity C-reactive protein (CRP), reactive oxygen species (ROS), γ-GT, IGF-1 and insulin-like growth factor binding protein 3 (IGFBP-3). IGF-1/IGFBP-3 was used as an estimate of bioavailable IGF-1. Total IGF-1 was similar between men and women (p=0.10), however, bioavailable IGF-1 was lower in women (p<0.001). In multivariate-adjusted analyses, IGF-1/IGFBP-3 was inversely associated with the number of metabolic syndrome components in both sexes (men: β=- 0.11; p=0.013 and women: β=- 0.17; p=0.003). Upon inclusion of ROS, γ-GT and CRP, significance was lost. In patients without diabetes, the results for men changed marginally, but were consistent for women. We found an inverse association between bioavailable IGF-1 and the number of metabolic syndrome components. But the relationship was dependent on oxidative stress, liver dysfunction and inflammation, suggesting underlying processes by which the metabolic syndrome attenuates IGF-1.

Insulin-like growth factors (IGF-I and IGF-II) are potent mitogens for breast cancer cells. IGF bioactivity is influenced by IGF binding proteins (IGFBPs). In vitro, most breast cancer cell lines express and secrete IGFBP-4. Sense and antisense complementary DMA of human IGFBP-4 were ligated into a mammalian expression vector and transfected into MCF-7 cells in order to investigate the role of IGFBP-4 on breast cancer cell proliferation in vitro and in vivo. IGFBP-4 concentrations were 4-8-fold higher in conditioned media (CM) of sense IGFBP-4 transfected cells compared to control cells, while IGFBP-4 concentrations in the CM of antisense IGFBP-4 transfected cells were lower than those present in the CM of control cells. Basal growth of sense IGFBP-4 transfected cells (S11) in media supplemented with 0.5% fetal bovine serum was significantly lower (P<0.01) than that of a vector-transfected control (C13) and antisense IGFBP-4 transfected cells (AS4). Loss of IGF but not EGF responsiveness in S11 cells was observed 48 h after exposure to these mitogens. Equal response to Des (1-3) IGF-I (an IGF-I analogue with reduced affinity for IGF binding proteins) was observed for C13, S11 and AS4 cells, suggesting that loss of responsiveness to IGFs by S11 cells is a consequence of IGFBP-4 expression. The in viva proliferation of S11 was significantly (P<0.01) less than that of control C13 and AS4 cells in both lit/lit (IGF-I deficient) or lit/+ (IGF-I replete) hosts. These data demonstrate that IGFBP-4 expression influences breast cancer behaviour.

Objective: Because most publications on growth and development deal with children with zinc deficiency, we decided to study the effects of this micronutrient on the secretion of growth hormone (GH), insulin-like growth factor 1 (IGF1), insulin-like growth factor binding protein 3 (IGFBP3), osteocalcin (OCN), and alkaline phosphatase (ALP) in healthy and eutrophic children. This study is original because the methodology was unique.Methods: Forty schoolchildren participated in the study, 17 females and 23 males, aged 8 and 9 years. The study was carried out during a 3-month period. It was characterized as a triple-blind randomized controlled trial. The children were divided in a control group (20 schoolchildren using 10% sorbitol) and experimental group (20 schoolchildren using zinc). All were submitted to oral zinc supplementation (10 mg Zn/day) and venous zinc administration (0.06537 mg Zn/kg of body weight). Blood samples were collected at 0, 60, 120, 180, and 210 min. All schoolchildren were also submitted to anthropometric, clinical, and dietetic assessments as well as biochemistry analyses.Results: Oral zinc supplementation in the experimental group (1) stimulated an increase in the consumption of protein and fat (p = 0.0007, p < 0.0001, p < 0.0001, respectively), (2) increased basal serum zinc (p < 0.0001), (3) increased plasma ALP (p = 0.0270), and (4) showed a positive correlation for IGF1, IGFBP3, and OCN, comparing before and after oral zinc supplementation (p = 0.0011, p < 0.0001, p < 0.0446, respectively). During zinc administration, plasma IGF1 and IGFBP3 increased significantly in the experimental group (p = 0.0468, p < 0.0001, respectively). Plasma GH increased in the experimental group but without statistical difference comparing before and after oral zinc supplementation.Conclusions: Zinc supplementation stimulated an increase in the consumption of some macronutrients and basal serum zinc and improved plasma alkaline phosphatase levels. Zinc administration increased hormones of the GH-IGF1 system.