Growth Hormone Administration Research Articles

The pattern of growth hormone action in the mouse brain.

Growth hormone (GH) acts in numerous organs expressing the GH receptor (GHR), including the brain. However, the mechanisms behind the brain's permeability to GH and how this hormone accesses different brain regions remain unclear. It is well-known that an acute GH administration induces phosphorylation of the signal transducer and activator of transcription 5 (pSTAT5) in the mouse brain. Thus, the pattern of pSTAT5 immunoreactive cells was analyzed at different time points after intraperitoneal or intracerebroventricular GH injections. After a systemic GH injection, the first cells expressing pSTAT5 were those near circumventricular organs, such as arcuate nucleus neurons adjacent to the median eminence. Both systemic and central GH injections induced a medial-to-lateral pattern of pSTAT5 immunoreactivity over time, as GH-responsive cells were initially observed in periventricular areas and were progressively detected in lateral brain structures. Very few choroid plexus cells exhibited GH-induced pSTAT5. Additionally, Ghr mRNA was poorly expressed in the mouse choroid plexus. In contrast, some tanycytes lining the floor of the third ventricle expressed Ghr mRNA and exhibited GH-induced pSTAT5. The transport of radiolabeled GH into the hypothalamus did not differ between wild-type and dwarf Ghr knockout mice, indicating that GH transport into the mouse brain is GHR-independent. Also, single-photon emission computed tomography confirmed that radiolabeled GH rapidly reaches the ventral part of the tuberal hypothalamus. In conclusion, our study provides novel and valuable information about the pattern and mechanisms behind GH transport into the mouse brain.

Exogenous growth hormone (GH) increases dimension and reduces strength of vertebrae in Atlantic salmon (Salmo salar)

Growth hormone (GH) administration increases bone strength in rats, mainly through alterations of the dimensional proportions of vertebrae. However, similar knowledge is lacking in other clades. In order to pursue this, Atlantic salmon were fed diets with high or low vitamin C and E and administered a slow-release implant of bovine GH.While neither the diets or the GH treatment affected growth, GH reduced condition factor and carcass-somatic index, and increased the hepatosomatic and visceral-somatic indexes. GH had an impact on the dimensional proportions of the vertebrae and increased the relative dorso-ventral and lateral vertebra diameters. Moreover, GH decreased the mechanical strength of the vertebra, both with (modulus of elasticity, failure point) and without (stiffness) normalizing the mechanical data for the dimensions of the vertebrae. Diet did not impact on the vertebra morphometry or mechanical strength. RNA-seq of vertebra centra show that several genes associated with bone growth and remodelling were affected by GH, while there was an interactive effect between diet vitamin level and GH on several genes associated with lipid metabolism.The data may suggest that exogenous GH affects the bone cellular mechanisms of Atlantic salmon postsmolts in such a way that their vertebrae increase in diameter but not length, not disturbing growth in body length. The GH and diet effects on lipid metabolism associated genes indicate a complex regulation of the lipids stored inside the vertebral column by endocrine and nutritional factors.

Can Human Growth Hormone Accelerate Tendon and Ligament Injury Recovery?

Studies involving human fibroblasts and use of human growth hormone (HGH) administration for injury recovery are limited. It is plausible that if the administration of HGH to human cells increased cellular proliferation and differentiation, then HGH might be able to assist in accelerating recovery from injury. HGH will increase proliferation and differentiation of human tendon and ligament fibroblasts in vitro based on both a single-dose and a sustained-dose model of HGH administration. Basic science cellular study. Human tendon and ligament tissue were harvested from 24 patients. Tissue samples were digested with type I collagenase to isolate the target cell types. HGH was administered directly to isolated cells at doses ranging from 100 pg/mL to 10 µg/mL, either in a single-dose or a sustained-dose model. Proliferation was analyzed at days 4 and 7. Differentiation of ligament and tendon fibroblasts was assessed at day 14. Administration of a single-dose of HGH to both cell types demonstrated similar or inferior cellular proliferation compared with controls after 7 days. For the sustained-dosing model of ligament fibroblasts, only the 100 ng/mL concentration demonstrated at least statistically similar or improved proliferation compared with controls. When examining the 100 ng/mL HGH concentration with larger sample sizes, cellular proliferation was not improved over controls for any cell type for the single- or sustained-dosing models. Proliferation for tendon fibroblasts was either similar or inferior to the control group at all concentrations of HGH. There was no clear dose-response relationship demonstrating enhanced collagen production with administration of HGH to suggest it enhances injury recovery. HGH administered to human tendon and ligament fibroblasts does not appear to positively affect cellular proliferation and differentiation. This study does not support the use of HGH for accelerating recovery from injury.

Growth hormone stimulates the in vitro development and establishment of Haemonchus contortus in sheep

The physiologic increase in some sex hormones has been associated with an increase in the parasite load caused by Haemonchus contortus in ewes, especially prolactin. In lambs that are especially susceptible to hemonchosis, the levels of sex hormones are low; in contrast, the levels of another pituitary hormone, growth hormone (GH), which is structurally very similar to prolactin, are high. In this study, the in vitro and in vivo effects of GH on H. contortus larvae development and establishment were evaluated. The addition of 20 ng/mL GH for 5 and 10 days to cultures of H. contortus larvae induced an enlargement (p<0.01) and an L3/L4 molting rate (p<0.03) greater than that of untreated larvae or those treated with other concentrations of the hormone. Flow cytometry showed that 3.8% of the largest and most complex cells of newly obtained larvae of H. contortus were positive for the GH receptor, and by immunofluorescence with confocal microscopy, it was observed that these receptors are located in the intestinal region larvae. In the in vivo assay, the administration of recombinant GH to gonadectomized lambs produced an increase in FEC (p<0.03), the number of female adult worms in the abomasum (p<0.05) and the levels of specific antibodies (p<0.04) in relation to the control lambs; however, it did not affect the fertility of H. contortus females. Although many factors affect the development and implantation of H. contortus in the abomasum of sheep, the results of this study strongly suggest that GH participates in the development and establishment of the parasite in sheep, mainly in young sheep.

Development of nano-liposomal human growth hormone as a topical formulation for preventing uvb-induced skin damage

Due to its involvement in skin maintenance and repair, topical administration of recombinant human growth hormone (rhGH) is an interesting strategy for therapeutic purposes. We have formulated and characterized a topical rhGH-loaded liposomal formulation (rhGH-Lip) and evaluated its safety, biological activity, and preventive role against UVB-induced skin damage. The rhGH-Lip had an average size and zeta potential of 63 nm and −33 mV, respectively, with 70 % encapsulation efficiency. The formulation was stable at 4 °C for at least one year. The SDS-PAGE and circular dichroism results showed no structural alterations in rhGH upon encapsulation. In vitro, studies in HaCaT, HFFF-2, and Ba/F3-rhGHR cell lines confirmed the safety and biological activity of rhGH-Lip. Franz diffusion cell study showed increased rhGH skin permeation compared to free rhGH. Animal studies in nude mice showed that liposomal rhGH prevented UVB-induced epidermal hyperplasia, angiogenesis, wrinkle formation, and collagen loss, as well as improving skin moisture. The results of this study show that rhGH-Lip is a stable, safe, and effective skin delivery system and has potential as an anti-wrinkle formulation for topical application. This study also provides a new method for the topical delivery of proteins and merits further investigation.

GH and IGF-1 in skin interstitial fluid and blood are associated with heat loss responses in exercising young adults.

Sweat glands and cutaneous vessels possess growth hormone (GH) and insulin-like growth factor 1 (IGF-1) receptors. Here, we assessed if exercise increases GH and IGF-1 in skin interstitial fluid, and whether baseline and exercise-induced increases in GH and IGF-1 concentrations in skin interstitial fluid/blood are associated with heat loss responses of sweating and cutaneous vasodilation. Sixteen young adults (7 women) performed a 50-min moderate-intensity exercise bout (50% VO2peak) during which skin dialysate and blood samples were collected. In a sub-study (n = 7, 4 women), we administered varying concentrations of GH (0.025-4000ng/mL) and IGF-1 (0.000256-100µg/mL) into skin interstitial fluid via intradermal microdialysis. Sweat rate (ventilated capsule) and cutaneous vascular conductance (CVC) were measured continuously for both studies. Exercise increased sweating and CVC (both P < 0.001), paralleled by increases of serum GH and skin dialysate GH and IGF-1 (all P ≤ 0.041) without changes in serum IGF-1. Sweating was positively correlated with baseline dialysate and serum GH levels, as well as exercise-induced increases in serum GH and IGF-1 (all P ≤ 0.044). Increases in CVC were not correlated with any GH and IGF-1 variables. Exogenous administration of GH and IGF-1 did not modulate resting sweat rate and CVC. (1) Exercise increases GH and IGF-1 levels in the skin interstitial fluid, (2) exercise-induced sweating is associated with baseline GH in skin interstitial fluid and blood, as well as exercise-induced increases in blood GH and IGF-1, and (3) cutaneous vasodilation during exercise is not associated with GH and IGF-1 in skin interstitial fluid and blood.

Multi-omics analysis of a fatty liver model using human hepatocyte chimeric mice

We developed a fatty liver mouse model using human hepatocyte chimeric mice. As transplanted human hepatocytes do not respond to mouse growth hormone (GH) and tend to accumulate fat, we hypothesized that addition of human GH would alter lipid metabolism and reduce accumulation of fat in the liver even when fed a high-fat diet. Six uPA/SCID chimeric mice were fed a high-fat GAN diet to induce fatty liver while six were fed a normal CRF1 diet, and GH was administered to three mice in each group. The mice were euthanized at 8 weeks, and human hepatocytes were extracted for RNA-Seq, DIA proteomics, and metabolomics analysis. Abdominal echocardiography revealed that the degree of fatty liver increased significantly in mice fed GAN diet (p < 0.001) and decreased significantly in mice treated with GH (p = 0.026). Weighted gene correlation network analysis identified IGF1 and SEMA7A as eigengenes. Administration of GH significantly reduced triglyceride levels and was strongly associated with metabolism of amino acids. MiBiOmics analysis identified perilipin-2 as a co-inertia driver. Results from multi-omics analysis revealed distinct gene expression and protein/metabolite profiles in each treatment group when mice were fed a high-fat or normal diet with or without administration of GH.

The Effect of Human Growth Hormone Treatment on the Development of Slipped Capital Femoral Epiphysis: A Cohort Analysis With 6 Years of Follow-up.

Slipped capital femoral epiphysis (SCFE) is a common hip disorder in adolescents that can result in substantial complications, impacting the quality of life. Human Growth Hormone (HGH) administration may elevate the risk of SCFE, though the relationship remains unclear. Clarifying this association could enable better monitoring and earlier diagnosis of SCFE in patients receiving HGH. The aim of the study is to investigate the association between HGH administration and the incidence of SCFE. This retrospective cohort study utilized data from the TriNetX research database from January 2003 to December 2022. The study included 2 cohorts: an HGH cohort including 36,791 patients aged below 18 years receiving HGH therapy and a control group consisting of patients who did not receive HGH therapy. A 1:1 propensity score matching technique was employed to ensure comparability between the HGH and no-HGH cohorts. The primary outcome measure was the development of SCFE identified by International Classification of Diseases codes. For comparative analysis, both risk ratios (RR) and hazard ratios were computed to evaluate the association between HGH therapy and the development of SCFE. The HGH cohort had an increased risk of SCFE compared with the no-HGH cohort (RR: 3.5, 95% CI: 2.073, 5.909, P <0.001) and had an increased hazard of developing SCFE (hazard ratio: 2.627, 95% CI: 1.555, 4.437, P <0.001). Patients with higher exposure to HGH (defined as >10 prescriptions) had an RR of 1.914 (95% CI: 1.160, 3.159, P =0.010) when compared with their counterparts with ≤10 prescriptions. In the largest study to date, HGH administration was associated with an elevated risk of SCFE in children in a dose-dependent manner. Level III-therapeutic retrospective cohort study.

Evaluation of the anticonvulsant and neuroprotective effect of intracerebral administration of growth hormone in rats

IntroductionThe growth hormone (GH) has been reported as a crucial neuronal survival factor in the hippocampus against insults of diverse nature. Status epilepticus (SE) is a prolonged seizure that produces extensive neuronal cell death. The goal of this study was to evaluate the effect of intracerebroventricular administration of GH on seizure severity and SE-induced hippocampal neurodegeneration. MethodologyAdult male rats were implanted with a guide cannula in the left ventricle and different amounts of GH (70, 120 or 220ng/3μl) were microinjected for 5 days; artificial cerebrospinal fluid was used as the vehicle. Seizures were induced by the lithium–pilocarpine model (3mEq/kg LiCl and 30mg/kg pilocarpine hydrochloride) one day after the last GH administration. Neuronal injury was assessed by Fluoro-Jade B (F-JB) staining. ResultsRats injected with 120ng of GH did not had SE after 30mg/kg pilocarpine, they required a higher number of pilocarpine injections to develop SE than the rats pretreated with the vehicle, 70ng or 220ng GH. Prefrontal and parietal cortex EEG recordings confirmed that latency to generalized seizures and SE was also significantly higher in the 120ng group when compared with all the experimental groups. FJ-B positive cells were detected in the hippocampus after SE in all rats, and no significant differences in the number of F-JB cells in the CA1 area and the hilus was observed between experimental groups. ConclusionOur results indicate that, although GH has an anticonvulsive effect in the lithium–pilocarpine model of SE, it does not exert hippocampal neuroprotection after SE.

Complications of Growth Hormone administration in Poor Ovarian Reserve undergoing ICSI. A Randomized Control study

Complications of Growth Hormone administration in Poor Ovarian Reserve undergoing ICSI. A Randomized Control study

The outcomes of growth hormone therapy in the obstructive sleep apnea parameters of Prader-Willi syndrome patients: a systematic review.

Prader-Willi syndrome is a serious genetic condition, capable of causing endocrinological imbalance, which has as one of its main treatments the growth hormone therapy. However, this therapy still causes some uncertainty concerning its effects on the respiratory parameters of those patients, especially in cases of obstructive sleep apnea, therefore, presenting a need for the analysis of the relationship between the therapy and the otolaryngologic condition. A systematic review following the PRISMA model was developed, with searches for keywords made in the databases PubMed (MEDLINE), Scopus, and Web of Science and registration in the PROSPERO platform (CRD42023404250). Three randomized controlled trials were considered eligible for inclusion in the review. None of the studies demonstrated statistically significant modifications in the obstructive sleep apnea parameters of Prader-Willi patients related to the growth hormone administration. Growth hormone therapy is safe for Prader-Willi syndrome patients when analyzing their obstructive sleep apnea parameters.

Can diffusion tensor imaging unlock the secrets of the growth plate?

"How tall will I be?" Every paediatrician has been asked this during their career. The growth plate is the main site of longitudinal growth of the long bones. The chondrocytes in the growth plate have a columnar pattern detectable by diffusion tensor imaging (DTI). DTI shows the diffusion of water in a tissue and whether it is iso- or anisotropic. By detecting direction and magnitude of diffusion, DTI gives information about the microstructure of the tissue. DTI metrics include tract volume, length, and number, fractional anisotropy (FA), and mean diffusivity. DTI metrics, particularly tract volume, provide quantitative data regarding skeletal growth and, in conjunction with the fractional anisotropy, be used to determine whether a growth plate is normal. Tractography is a visual display of the diffusion, depicting its direction and amplitude. Tractography gives a more qualitative visualization of cellular orientation in a tissue and reflects the activity in the growth plate. These two components of DTI can be used to assess the growth plate without ionizing radiation or pain. Further refinements in DTI will improve prediction of post-imaging growth and growth plate closure, and assessment of the positive and negative effect of treatments like cis-retinoic acid and growth hormone administration.

The Impact of Growth Hormone Co-Treatment Duration on Outcomes in IVF/ICSI Cycles Among Poor Ovarian Responders.

The efficiency of in vitro fertilization is improved by growth hormone (GH) during ovarian stimulation. Additionally, patients with diabetes experience impaired insulin resistance and compromised glucose tolerance, which further exacerbate their condition. Due to these side effects, in this study, the duration of GH treatment was compared in IVF/ICSI cycles among poor ovarian responders. In this study, POSEIDON criteria were used to choose patients. Subcutaneous administration of gonadotropin-releasing hormone (GnRH) antagonist was done beginning on the sixth day of the cycle and continuing through the day of human chorionic gonadotropin (hCG) injection. In one group, GH was administered 4 units/day from the 2nd day of the cycle until hCG injection, and in another group, the first dose was administered on the 6th day of the cycle. Following the administration of hCG, which lasted from 24 to 36 hr, oocytes were retrieved with the support of B-mode sonography. In our analysis, no significant differences were observed between the two groups in terms of the number of retrieved oocytes, metaphase II oocytes, and quality of grade A and B embryos. The results show that the treatment or conditions did not have a significant impact on the outcomes among the studied groups. Our findings indicate that a shorter duration of GH administration can yield similar outcomes compared to a longer duration in IVF/ICSI cycles involving poor ovarian responders. This result holds the potential for a more cost-effective and patient-friendly approach in managing assisted reproductive technology procedures. It may lead to reduced side effects and improved adherence to medication regimens in patients.

Growth hormone promotes the reconstruction of injured axons in the hypothalamo-neurohypophyseal system.

JOURNAL/nrgr/04.03/01300535-202410000-00026/figure1/v/2024-02-06T055622Z/r/image-tiff Previous studies have shown that growth hormone can regulate hypothalamic energy metabolism, stress, and hormone release. Therefore, growth hormone has great potential for treating hypothalamic injury. In this study, we established a specific hypothalamic axon injury model by inducing hypothalamic pituitary stalk electric lesions in male mice. We then treated mice by intraperitoneal administration of growth hormone. Our results showed that growth hormone increased the expression of insulin-like growth factor 1 and its receptors, and promoted the survival of hypothalamic neurons, axonal regeneration, and vascular reconstruction from the median eminence through the posterior pituitary. Altogether, this alleviated hypothalamic injury-caused central diabetes insipidus and anxiety. These results suggest that growth hormone can promote axonal reconstruction after hypothalamic injury by regulating the growth hormone-insulin-like growth factor 1 axis.

Effect of growth hormone administration on ameliorating pregnancy outcome in women with advanced maternal age and exploration of its optimized utilization.

Age-related fertility decay is a great challenge for clinicians. Growth hormone (GH) supplementation has been studied as an adjuvant since late 1980s. However, it has not come to a consensus on the GH administration due to the ambiguous efficacy among studies with different enrolled population and dosage regime. A self-controlled retrospective study was conducted on women with advanced maternal age who underwent at least a previous cycle without GH (GH-) and a subsequent cycle with GH co-treatment (GH+). The ovarian stimulation parameters and outcomes were compared between the two cycles and logistical analysis was applied to further explore the association between GH administration protocol as well as other clinical parameters and cumulative live birth in GH+cycle. A total of 150 women aged 35-43 were included. The number of oocytes retrieved, MII oocytes, 2PNs, transferrable embryos and good-quality embryos in GH+ significantly increased (p < 0.001). The proportion of cycles with no transferrable embryos was significantly reduced in GH+ cycle compared with previous GH- cycle (3 vs. 32; p < 0.001). GH co-treatment cycles showed significantly higher clinical pregnancy rates (43.75% vs. 6.06%; 38.35% vs. 12.04%, p < 0.001), live birth rates (29.17% vs. 0; 27.07% vs. 0, p < 0.001) in both fresh and frozen-thawed embryo transfer cycle. Cumulative live birth rate of the GH+ cycle reached 33.33%. Use of GH prior to Gn stimulation and lasting until the hCG day seemed to achieve a higher successful live birth rate (OR 2.312, 95%CI 1.074-5.163, p=0.032). GH supplementation could ameliorate pregnancy outcome in women with advanced maternal age. Dosage regimen of long-term pretreatment prior to Gn stimulation (4 IU every other day) and 4 IU per day until hCG day may of greater efficacy compared with concurrent administration with Gn. Additionally, it's worthy of exploring whether an individualized dosage regimen based on the IGF or IGFBP level of patient would be more reasonable and effective. More well-designed prospective trials with large sample size and fundamental experiments on the mechanism are required to testify findings above.

FRI020 Adipocyte Subpopulations Regulate Growth Hormone-induced Lipolysis And Insulin Resistance

Abstract Disclosure: S. Siyar: None. J. Huang: None. R. Sharma: None. J.J. Kopchick: None. V. Puri: None. K.Y. Lee: None. Growth Hormone (GH) administration has long been known to increase lipolysis in adipose tissue leading to increased circulating free fatty acid levels and insulin resistance. Previous studies from our lab have found that this effect is mediated, at least in part, through transcriptional repression of the lipid droplet associated protein Fat specific protein (FSP27 also known as CIDEC). Furthermore, recent studies suggest that within a single adipose tissue depot there are different subpopulations of adipocytes. We have identified three distinct subpopulations of adipocytes with unique gene expression profiles and metabolic activities. We have found that one of these subpopulations of adipocytes, termed Type 2 adipocytes, are highly responsive to GH stimulation. In order to assess the physiological role of GH-mediated lipolysis mediated by this subpopulation, we specifically expressed human FSP27 (hFSP27) in Type 2 adipocytes (Type2Ad-hFSP27tg mice). Type2AdhFSP27tg mice had reduced systemic plasma glycerol release after acute GH treatment, and improvement in acute, but not chronic, GH-induced glucose intolerance. These mice exhibited an 45% increase in fat mass and significant increase in adipocyte cell size further indicating a decreased lipolytic response to GH. This decreased lipolytic response was associated with improved hepatic insulin signaling and insulin-induced gene expression in Type2Ad-hFSP27tg mice. Taken together, these results indicate that specifically targeting a subpopulation of adipocytes is sufficient to reduce GH-induced lipolysis and insulin resistance and may provide a platform for improved medical therapies for growth and endocrine disorders. Presentation: Friday, June 16, 2023

THU052 Serum Growth Hormone Increases At The Onset Of Lactation And Promotes Mitochondrial Activity In Human Mammary Cells

Abstract Disclosure: T. Elajnaf: None. H. Rostom: None. X. Meng: None. A. Fry: None. F. Hannan: None. Growth hormone (GH) administration is reported to increase milk yield in breastfeeding women. However, the role of endogenous GH in human lactation is unknown. We investigated whether serum GH is associated with the initiation of lactation after child birth, and recruited n=30 pregnant women (age range 24-41 years) following informed consent (1). Serum GH was measured at 36 weeks’ gestation and during postpartum days 1-4. All women had term births and initiated lactation between postpartum days 2-4. The mean maternal serum GH value progressively increased from 0.2±0.01 mIU/L at 36 weeks’ gestation to a peak value of 0.9±0.2 mIU/L on postpartum day-3 (p&amp;lt;0.0001), with serum GH then decreasing to 0.2±0.03 mIU/L by postpartum day-4. We hypothesised that this early postpartum rise in serum GH may increase mammary metabolism in order to stimulate milk synthesis after child-birth. Reverse transcription-quantitative PCR (RT-qPCR) demonstrated that lactating human mammary epithelial cells (HMECs) isolated from breast milk express the GH receptor. We next assessed the effects of GH in cultured HMECs. Recombinant human GH (rhGH) caused a dose-dependent increase in the phosphorylation of Akt, which is a key signalling protein required for initiating lactation. Thus, 50ng/mL and 500ng/ml rhGH caused ∼1.5-fold and ∼2-fold increases in Akt phosphorylation, respectively (p&amp;lt;0.05, n=4 experiments). We further evaluated the effects of rhGH on HMECs by untargeted proteomics involving nano liquid chromatography and tandem mass spectrometry. This demonstrated that the major mammary cell biological processes induced by GH involve the mitochondria. Indeed, HMECs treated with rhGH for 8 hours showed a significant upregulation of mitochondrial proteins involved in electron transport chain assembly, namely COQ9 (&amp;gt;4-fold increase, p&amp;lt;0.05) and IBA57 (&amp;gt;4-fold increase, p&amp;lt;0.05); and upregulation of CHCHD3 (6-fold increase, p&amp;lt;0.05), which influences mitochondrial cristae structure. We assessed whether these mitochondrial protein changes affect mammary cell respiration. Extracellular O2, which is an indicator of oxidative phosphorylation, was measured in cultured HMECs treated with 50ng/mL rhGH for up to 5 days. Administration of 50ng/mL rhGH caused a significant increase in the rate of O2 consumed by these cells (579±28 vs. 456±14 pmol O2/min/106 cells for control HMECs, p&amp;lt;0.01, n=4 experiments), consistent with increased oxidative phosphorylation. In summary, these clinical and cellular studies highlight a pivotal role for GH in promoting mammary cellular metabolism at the onset of lactation. Reference: (1) Rostom, H. et al. Protocol for an observational study investigating hormones triggering the onset of sustained lactation: the INSIGHT study. BMJ Open 12, e062478. Presentation: Thursday, June 15, 2023

A combined top-down and bottom-up LC-HRMS/MS method for the quantification of human growth hormone in plasma and serum

ObjectiveThe precise and accurate quantification of human growth hormone (GH) in plasma/ serum is crucial for the diagnosis and treatment of diseases like GH deficiency or acromegaly. However, the ligand-binding assays (LBAs) currently used for routine testing show considerable methodological variability. Here, we present a complementary, combined top-down and bottom-up LC-MS-based method to quantify (intact) GH in plasma and serum, which concurrently provides a basis for a MS-based analysis of GH in doping controls. DesignExtraction of GH from plasma/ serum was accomplished by protein precipitation, followed by an immunocapture step using protein A-coupled magnetic beads and a polyclonal anti-GH antibody. The intact protein was subsequently analyzed top-down on a 2D-LC-HRMS/MS system. In addition, sample extracts were digested with trypsin and analyzed for signal peptides corresponding to ‘total’, 22 kDa and 20 kDa GH (bottom-up). Both assays were validated according to current guidelines and compared to the GH isoform differential immunoassay used in routine doping control analysis. GH concentrations in serum samples of healthy adults, patients with acromegaly, and in samples obtained after administration of recombinant GH were analyzed as proof-of-principle. ResultsThe intact monomeric 22 kDa isoform of GH was selectively quantified in a representative working range of 0.5 to 10 ng/ml by top-down LC-HRMS/MS. Subsequent bottom-up analysis provided additional data on ‘total’ and 20 kDa GH. Top-down and bottom-up assay results for the 22 kDa isoform correlated well with the corresponding immunoassay results (R2 > 0.95). For a possible application of the method in an anti-doping context, the ratio between 22 kDa and ‘total’ GH was evaluated, indicating differences between the various donor groups, but only with limited significance. ConclusionThe top-down and bottom-up LC-HRMS/MS method developed here presents a valuable tool for the quantification of GH in plasma/ serum complementary to established LBAs used at present in clinical measurements. Albeit the examination of the GH isoform proportions by the LC-MS method does not yet allow for the assessment of GH abuse, the obtained findings provide an important basis to enable LC-MS-based GH analysis of doping control samples in the future.

Impact of growth hormone on physical performance

Growth hormone (GH) is an anabolic hormone produced by the pituitary gland. The action of growth hormone is not only to promote growth in children, but it has a significant effect on metabolism and body composition also in adults. Growth hormone deficiency (GHD) leads to physical impairment (worsen muscle strength, aerobic and anaerobic capacity) and altered body composition - with increased fat and reduced lean body mass, particularly reduced skeletal muscle mass. On the other hand, GH excess in patients with acromegaly impairs physical function, especially aerobic capacity and muscle strength irrespective of GH-dependent muscle hypertrophy. There is unclear data about GH impact on physical performance among healthy populations. Some studies showed improvement in anaerobic capacity during recombinant human GH (rh-GH) administration, others showed no significant difference. Muscle strength did not improve after rh-GH administration among healthy adults. However, recombinant GH is abused by professional and recreational athletes to improve their physical performance.

Gonadotropin-releasing hormone and growth hormone act as anti-inflammatory factors improving sensory recovery in female rats with thoracic spinal cord injury.

The potential for novel applications of classical hormones, such as gonadotropin-releasing hormone (GnRH) and growth hormone (GH), to counteract neural harm is based on their demonstrated neurotrophic effects in both in vitro and in vivo experimental models and a growing number of clinical trials. This study aimed to investigate the effects of chronic administration of GnRH and/or GH on the expression of several proinflammatory and glial activity markers in damaged neural tissues, as well as on sensory recovery, in animals submitted to thoracic spinal cord injury (SCI). Additionally, the effect of a combined GnRH + GH treatment was examined in comparison with single hormone administration. Spinal cord damage was induced by compression using catheter insufflation at thoracic vertebrae 10 (T10), resulting in significant motor and sensory deficits in the hindlimbs. Following SCI, treatments (GnRH, 60 μg/kg/12 h, IM; GH, 150 μg/kg/24 h, SC; the combination of both; or vehicle) were administered during either 3 or 5 weeks, beginning 24 h after injury onset and ending 24 h before sample collection. Our results indicate that a chronic treatment with GH and/or GnRH significantly reduced the expression of proinflammatory (IL6, IL1B, and iNOS) and glial activity (Iba1, CD86, CD206, vimentin, and GFAP) markers in the spinal cord tissue and improved sensory recovery in the lesioned animals. Furthermore, we found that the caudal section of the spinal cord was particularly responsive to GnRH or GH treatment, as well as to their combination. These findings provide evidence of an anti-inflammatory and glial-modulatory effect of GnRH and GH in an experimental model of SCI and suggest that these hormones can modulate the response of microglia, astrocytes, and infiltrated immune cells in the spinal cord tissue following injury.